PAGE 11

 Thus, thought is existence. More than that, so far as we are concerned, existence is thought, all our conceptions of existence being some kind or other of thought. Do not for a moment suppose that these are mere paradoxes or subtleties. A little reflection upon the commonest facts is irrefragable truth. For example, I take up a marble, and I find it to be a red, round, hard, single body. We call the redness, the roundness, the hardness, and the singleness, ‘qualities’ of the marble. It sounds, at first, that the highest sculpting form of absurdity might be to say that all these qualities are modes of our own consciousness, which cannot even be conceived to exist in the marble. Yet consider the redness, with which to begin. How does the sensation of redness arise? The waves of intuitive certainty, may it attenuated matter, the particles of which are vibrating with vast rapidity, but with very different velocities, strike upon the marble, and those that vibrate with a particular velocity are thrown off from its surface in all directions. The optical apparatus of the eye gathers some of these together, and gives them such a course that they impinge upon the surface of the retina, which is a singularly delicate apparatus connected with the end of the fibres of the optic nerve. The impulses of the attenuated matter, or ether, affect this apparatus and the fibres of the optic nerve in a certain way; and the change in the fibres of the optic nerve produces yet other changes in the brain; and these, in some fashion unknown to us, lead to the feeling, or consciousness of redness. If the marble could remain unchanged, and either the rate of vibration of the ether, or the nature of the retina, could be altered, the marble seems not red, but some other colour. There are many people who are what is called colour-blind, being unable to distinguish one colour from another. Such an one might declare our marble to be green. He would be quite as right in saying that it is green, as we are in declaring it to be red. Yet then, as the marble cannot can be both green and red, while, as this shows that the quality ‘redness’ must be of our consciousness and not in the marble.
 In like manners, since the roundness and the hardness are forms of our consciousness is easy, belonging to the groups that we call sensations of sight and touch. If the surface of the cornea were cylindrical, we should have a very different notion of a round body from that which we possess now.  If the strength of the fabric, and the force of the muscles of the body, were increased by some hundredfold, our proportional differences of consistency would possibly equal to that of some upcoming periphery where the marble would be as soft as a pellet of bread crumbs.
 Not only is it obvious that all these qualities are in us, but, if you will try, you will find it quite impossible to conceive of ‘blueness,’ ‘roundness,’ and ‘hardness’ as existing without a call for such consciousness, his frame reference is to some such consciousness as our own. Saying that even the might seem strange ‘singleness’ of the marble is about us, but simple experiments will show that this is veritably the case, and that our two most trustworthy senses may be made to contradict one another on this notable point. Hold the marble between the finger and thumb, and look at it in the ordinary way. Sight and touch agree that it is single. Now squint, and sight tells you that there are two marbles, while touch asserts that there is only one. Next, return the eyes to their natural position, and, having crossed the forefinger and the middle finger, put the marble between their tips. Then touch will declare that there are two marbles, while the naked eye says that there is only one. Our sense of touch proclaims our belief, however when we appear to it, just as imperatively as the naked eye does.
 Nevertheless, it may be said, the marble takes up a certain space that could not be occupied, while, by anything else. In other words, the marble has the primary quality of matter, extension. Surely this quality must be in the thing and not in our minds? Nonetheless, the reply must still be; whatever may, or may not, exist in the thing, all that we can know of these qualities is a state of consciousness. What we call extension is a consciousness of a relation between two, or more, affections of the sense of sight, or of touch. It is wholly inconceivable that what we call extension, is the branch of a progressional contingence and should exist independently of consciousness, as we knew it to be. Whether, this is inconceivability, it does so exist, or not, is a point on which I offer no opinion. Thus, whatever our marble may be, all that we can know of it is under the shape of a bundle of our own consciousness.
 Nor is our knowledge of anything we know or  feel more, or less, than a knowledge of states of consciousness. Our whole life is made up of such states. Some of these relational states as inferred by its cause we call ‘self’, and others to the cause or causes that may be comprehended under the title of ‘not-self.’ Nonetheless, inform that holds the existence neither of ‘self’ nor of that of which is ‘not-being-of-self’ have or can that we by any possibility have, any such unquestionable and immediate certainty, that we have of our relational states of consciousness, under which we can consider having been their effects. They are not immediately observed facts, but results of the application of the law of causation to those facts. Strictly speaking, the existence of a ‘self’ and of a ‘not-self’ are hypotheses by which we account for the facts of consciousness. They stand upon the same footing as the belief in the general trustworthiness of memory, and in the general constancy about A Nature-as hypothetical literature or academic summations for which acquires its doctorate to be acquainted and familiarized about its defending dissertation, only to be proven, or known with by way of its highest degree of certainty given by immediate consciousness, which, is, nevertheless, of the highest practical value, since the conclusions logically drawn are from them are always verifiably experienced.
 This, in my judgment, is the ultimate issue of Descartes' argument, bearing to point out that we have left Descartes himself some way behind us. He stopped at the famous formula, ‘I think, therefore I am.’ Yet, the concerning considerations will show this formula to be full of intertwining fibres and verbal dissimulations that only assimilates entanglement. In the first place, the conclusive ly idealistic term said to be, ‘therefore’ which has no deserving business, and must legitimately find its way home. Also, ‘I am’ of being assume in that ‘I think’, may from which it is simply another way of saying ‘I am thinking’ or ‘I am conscious.’ All the same, it is in the second place, ‘I think’ which is not one simple proposition, it is, that there are three distinct assertions rolled into one. The first of these is, something called ‘I exist,’ the second is, something called ’thought exists’ and the third is, ‘the thought is the result of the action of I-ness.’
 Now, it will be obvious to you, that the only one of these three propositions that can stand the Cartesian test of certainty is the second. It cannot be doubted, for the very doubt is an existent thought. However, the first and third, whether true or not, may be doubted, and have been doubted. For the assenter may be asked, How do you know that thought is not self-existent, or that a given thought is not to affect of its previous line of thinking, or given to something otherwise to some external power? A diversity of other questions, much more easily put than answered. Descartes, determined as he was to strip off all the garments that the intellect weaves for itself, forgot this gossamer shirt of the ‘self’ bringing of a greater detriment, and the ruin of his expression when he began to clothe himself again.
 Nevertheless, it is beside my purpose to dwell upon the minor peculiarities of the Cartesian philosophy. All I wish to put clearly before your minds thus far, is that Descartes, having commenced by declaring doubt to be a duty, found certainty in consciousness alone; and that the necessary outcome of his views is what may properly be termed Idealism; namely, the doctrine that, whatever the universe may be, all we can know of it is the picture presented to us by consciousness. This picture may be a true likeness–though how this can be is inconceivable; It may have no more resemblance to its cause than one of Bach's fugues has to the person who is playing it, than a piece of poetry has to the mouth and lips of a reciter. It is enough for all the practical purposes of human existence if we find that our trust in the representations of consciousness is verified by results. That, by their help, we are enabled ‘to walk surefootedly in this life.’
 Thus the method, or path that leads to truth, showed by Descartes, takes us straight to the Critical Idealism of his great successor Kant. It is that Idealism that declares the ultimate fact of all knowledge to be consciousness, or, in other words, a mental phenomenon. Consequently, affirms the highest of all certainties, and the only absolute certainty, to be the existence of mind. However, it is moreover that Idealism that refuses to make any speculative assertions, either positive or negative, find there parallel in what lies beyond consciousness. It accuses the subtle Berkeley of stepping beyond  the limits of knowledge when he declared that a substance of matter does not exist. Existence may paradoxically be for not as the arguments for which he is supposed to have vanquished into the Northern sea, but reasons hold to its existence for the sake of matter itself, only from which we were equally destructive to the existence of soul. Nevertheless, it refuses to listen to the jargon of more recent days about the ‘Absolute’ and all the other hypostasised adjectives, the initial letters of the names of which is generally printed are the capital letters, just as you give a Grenadier a bearskin cap, it much seems as to give the appearance of ponderosity for more than he is by nature.
 The path indicated and followed by Descartes, which we have previously been treading, leads through doubt to that critical Idealism that lies at the heart of modern metaphysical thought. Yet the ‘Discourse’ shows us another, and apparently very different, the path, which leads, quite as definitely, to that correlation of all the phenomena of the universe with matter and motion, which lies at the heart of modern physical thought, that most people call Materialism.
 The early part of the seventeenth century, when Descartes reached manhood, is an epoch of the intellectual life of manhood. Then, physical science suddenly strode into the arena of public and familiar thought, and openly challenged not only Philosophy and the Church, but that common ignorance that often passes by the name of Common Sense. The assertion of the  motion of the earth was a defiance to all three, and Physical Science threw down her glove by the hand of Galileo.
 Thinking of the immediate result of the combat is not pleasant, to see the defender of science, old, worn, and on his knees before the Cardinal Inquisitor, signing his name to what only he knew to be a lie. No doubt, the Cardinals rubbed their hands as they thought of themselves to how well they had silenced and discredited their adversary. Still, two hundred years have passed, and have long since diminished of any but one feeble or erroneous combatant. Physical Science sits crowned and enthroned as one legitimate ruler of the world in thought. Charity children would be ashamed not to know that the earth moves; while the Schoolmen are forgotten; and the Cardinals–well, the Cardinals are at the Ecumenical Council, still at their old business of trying to stop the movement of the world.
 According to Descartes, if we make errors in our thinking, it is our own fault. Human beings are given to a free will, and most substantially significant, and just a flawless part of our species. This free will acts independently to either affirm or deny, or pursue or shun any some thing. The free will acts properly when the will has access to knowledge and reason and can ‘perceive what is true with sufficient clarity and distinctness.’ To attain truth, and to act correctly, the will must rely on those perceptions that cannot come from anything, but rather, come from something, and that something must be from God in all his supreme perfection. God, in essence, must play the celestial orchestrator in any perception that is true. Following this path cannot lead one to err; that is, the path of humility that relies on one's God-given faculties and God himself to use the will properly.
 On the other hand, if freedom calls of the will, it  is confronted with something of which it has no knowledge, it will act indifferently. Without God and the knowledge of what is true, the will ‘easily turns away from the true and the good,’ leading to deception and sin. In addition, use of the will with only partial knowledge, that is, without full clarity and distinct perception based on knowledge, will also lead to error. Indifference and conjecturing or making speculative assertions are not true or false, it is a misuse of the will, even if by the change of chance it could possible take or give oneself of luck, the outcome happens upon the truth. The deliberation from illiteracy, is one who arrogantly relies only upon then immigrated transitions for which all unexcepted modulations in doings, occurs from those that are without truth only inaccessibly from God, thus, the make-upon of some unequivocal misuse of free will, are ultimately and undeniably, as merely of an error.
 Spinoza would disagree with Descartes' idea of the free will. While the will for Descartes uses the intellect freely (in the proper way), Spinoza asserts that ‘things could not have been produced by God in any other way or in other order than is the case.’ The will is not a free cause, but a necessary cause, because it is only a ‘definite mode of thinking’ and thus subject to the greater causal matrix. Since all causes in the matrix can be followed back to God as an absolutely infinite being, everything has its cause in God. While, not even God has freedom of the will, as he is constrained by his divine nature and can only act as his nature would have it-the only way it can be as it is perfectly so. Therefore, there are no error, no sin, and no deception. Everything simply is as it should be according to the perfection of God's divine nature.
 Substance is defined differently for Descartes, Spinoza and Leibniz contributing to the fundamental differences between their assertions in their philosophies. For Descartes, there are primarily three substances: God, thought and extension. For Spinoza there is only one substance: God. For Leibniz, there are two substances: God and monads. For each of these three, their concept of substance dramatically affects the outcomes of their philosophies and their explanations for the nature of the universe and our place in humanely, and we might consider ourselves as inseparable of it, and in our relation to God.
 Descartes' determination foreshadows to carry through his need to readily rethink along everything he has ever thought to be True and Right. In doing so, he realizes that the only thing he can really be sure of is his ability to think, thus affirming his existence, and the substance of thought. He bears to witness in the conditions of truth that he is in  himself from that which is a prefect God, and that God must be both omnipotent and benevolent. He can then determine that because God is not a great deceiver (deception is an attribute of imperfection not consistent with perfection), then extension is the third substance. There are some discussions regarding the ability of the two substances, thought and extension, to interact. Since effect can be caused by only the same kind of substance, having it of some connotation for being causally then seems impossible for thought and effectual of the body. However, Descartes asserts that at the smallest levels interaction does occur.
 Spinoza criticizes Descartes for not following through on his assertions about an infinite God. If God is infinite, then he must be absolutely infinite, that is ‘substance consisting of infinite attributes, each of which expresses eternal and infinite essence.’ Because God is also perfect in his divine nature, everything that is, is by that perfection and is only exactly as it can be. God, thought and extensions are not separate substances, but rather thought and extension are simply attributes of God, expressed through an infinite amount of finite modalities. The order and connection between thoughts correspond and those for extended things (as they are the same) according to an infinite causal matrix determined by God, the only absolutely infinite substance.
 Leibniz appeals to God as not only worthy of glory for his greatness and goodness, but his ability to create the most interesting reality from the simplest system. Leibniz proposes that God perpetuate this creation and by its infinite number in that of ‘monads.’ Each monads are a singular substance that ‘expresses the whole universe in its own way, and that all events, with all their circumstances and the whole sequence of external things, is included in its notion.’ There is a hierarchy of monads from the most simple and most confused, to the minds that are self-conscious and reflective, thus much less confused. When the perceptions of these infinite number of minds (monads) harmonize, the world arises as an emergent property based on well-founded phenomenons. Monads have no windows, that is, they do not interact. Nevertheless, again, they don't need to as each substance has within it a complete notion of itself. There is not a problem with the interaction of thought and extension, because there are only ‘monads.’
 Knowledge for Locke is the perception of the agreement or disagreement of ideas. Ideas are the object of thinking, and come from sensation and reflection. It is the quality of a subject that has the power to produce ideas in one's mind. Experience provides the foundation for knowledge as observations about the sensible qualities of the external physical world are perceived through the senses and understanding of the internal operations of one's mind are operations of the mind. Both processes can be reflected upon in one's mind. Ideas are only received via these two methods. The sensation that people are exposed too in a lifetime will affect their ability to both sense and reflect, that is, if they are not exposed they can neither sense nor reflect on sensation they never received, and some people will remain more confused than others about their sense experience and reflection due to their (lack of) focussed and attentively purposed. Further, because reflection requires attention, ideas resulting from reflection only surface later, and, again, to different degrees among different people based on their varied perspective, focus and attention.
 Simple ideas can be conceived by means of only one sense, more than one sense, by reflection only, or by all ways of sensation and reflection. Often these simple ideas don't even have a name. The mind is as an ‘empty cabinet’ ready for the passive reception of simple ideas. These simple ideas are neither created nor destroyed by the mind, but rather gathered into the mind through the senses or operations as such.
 Leibniz believed the intelligible world of ultimate knowables, the problems raised by the skeptic Hume coming after him. He has some words to say to Descartes, who came before Leibniz, was of his concern of whether the world is knowable, but proving that knowledge of the external world is possible so, he foregoes the thrust of his philosophy. He focussed so much on what he believed must be true that stripped-down ideas that leave no point unquestioned, ultimately to prove knowledge impossible, or justify it only after the most extreme doubt possible, was not with what he was concerned. This sector will rather focus on Leibniz's rationalism -his idea that our main apparatus for discovering and understanding the nature of the world comes from pure reason, and not through the senses.
 First, Leibniz believed it may have turned out that we did not know necessary truths such as ‘All green things are green.’ How is it that I know this proposition holds, even in some galaxy other than ours, on the other side of the universe? It was akin to a divine sort of magic to Leibniz that we should know any proposition that holds true under all circumstances and locations. He called it ‘an inborn light within us,’ which lets us cross the wide cosmos in one stroke of thought, and know beyond all doubt that all green things have always been green, no matter where on the earth or in the heavens, from the beginning of time to the end of the cosmos.
 So let us examine just how we know that all green things are green. We know it because we know if a green thing is not green, it was an error to call it a green thing in the subject, and it is not in fact green. On the other hand, we know that if a thing is green, it is green. Ultimately to deny the proposition would involve us in a contradiction. Let us not forget, that if it is thus to suppose that all examined emeralds have been green. Uniformity would lead us to expect that future emeralds will be green as well. However, now we can define a predicate grue: ‘x’ is gruing if and only if ‘x’ is examined before time ’t’ and is green, or ‘x’ is examined after time ‘t’ and is blue. Let ‘t’ refers to some time around the present. Then if newly examined emeralds are like previous ones in respect of being grue, they will be blue. We prefer blueness as a basis of prediction to glueyness, but why? An interrogative sentence, by its appearing involvements as a reference to a difference, this is just a parochial or language-relative judgement, there brings no language-independent standard of similarity to which to appeal. Other philosophers have not been convinced by this degree of linguistic relativism. What remains clear is that the possibility of these ‘bent’ predicates puts a decisive obstacle in face of purely logical and syntactical approaches to problems of ‘confirmation.’ So we know now as well of the place that given to respect may not otherwise be true, or that there are such things as true contradictions. Nevertheless, we know there are no such things as true contradictions, and so we know that all green things are green.
 Consequently the interrogative sentence comes to the boiling point from which its availabilities to answer of ‘how’ do we know there are no trued contradictions? We cannot prove this is true without assuming its truth in the first place, for any demonstration of any proposition is valid only if there are no true contradictions -the very things we are trying to prove. So to avoid begging the question, we cannot reason at all. That there are no true contradictions, then, cannot be demonstrated.
 How do we know there are no true contradictions? That is, would we know it if it were merely a quirk of our minds that we cannot comprehend a true contradiction, some arbitrary way our brains developed, that has nothing to do with objective reality? Could it be that we cannot simply conceive of a true contradiction in the way that our bodies cannot be sustained by eating stones? Is it merely an arbitrary aspect of the human organism that we cannot conceive of a true contradiction, than this being due to the nature of the world itself?
 One would never know this if it were so. We would go on reasoning and making rules of deductive logic that have nothing to do with what is true and false in nature itself, and only reflect arbitrary quirks of our psychological biology, so to speak, and what it can and cannot process as an organism that thinks.
 Nevertheless, most philosophers do not think there is much fruit to be had in thinking like this. To question the rule of non-contradictorily, that is, to deny its truth, rests upon assuming its truth as much as asserting its truth does. Aristotle solved the problem by saying if a man doubts that there are no true contradictions, if he speaks and reasons, he is assuming the principle's truth; so if he questions it let him remain silent, but if he speaks and argues he must assume there are no true contradictions to do so, and thus undermines his doubt of the principle. Put another way: we have no choice but to assume there is no true contradiction if we are to philosophize at all; for whether we use reason to deny the rule of non-contradiction or to assert its truth we are all asserting its truth as a prerequisite. This very discussion of the problem assumes the rule's truth, and so where I question its validity here, ironically, I assert its veracity, by the mere fact that I am using reason.
 So let us do what we must, and assume that it is complementary for the sake as drawn upon that we who infer that nature has some consistency of things. In themselves, we have in ruling of non-contradiction, for which case, are we to know of its truth? We, on the other hand, cannot explain in how we know it, only that we cannot conceive throughout in other respects. This is the ‘inborn light within us’ that allows us to cross time and space and know the nature of the other side of the cosmos, which Leibniz found so fascinating. Assuming the rule of non-contradiction is commentary on the true nature of things, it is certainly astounding that we should find a single principle that should apply to all places, times, dimensions and modes of being, from a mere act of thought. Certainly were the empiricist correct, but they would have a very difficult time explaining just how this ‘inborn light’ is possible. To say, that we have evolved as such as that we have become rationally ingested as to arrange by coordinative orders a set of communicative combinations that once had been lacking the  ability to conceive of a true contradiction, into which realms are arbitrarily biological quirks, that place the origin set to a certain position that positioned by its growth was held steadfast within the strangest formalities as set through causality, least of mention, that, in so doing, its resulting consequent from arbitrary displacement drew nothing but a marginal peripheral infraction of nature. To do so would be to question the objective veracity of the principle; perhaps we can just survive and leave more offspring if we believed there were no true contradictions, though it is not in fact true that there are none. Certainly to call it a result of evolution is to deny the very veracity of the principle, something impossible in philosophy if it is to be philosophy. Evolution works by preserving the ones who leave the most offspring, not preserving the ones who know the most truth.
 Before Kant, philosophy had two categories of knowledge: those propositions we know whose contrary implies a contradiction in terms, and those whose contrary didn't. ‘This apple is yellow’ doesn't have a contrary that implies a contradiction, while ‘All apples are apples’ does. Leibniz naturally found it more incredible that we could know the latter rather than the former; the former has no bearing on anything but that particular apple; it does not signify anything beyond the particular circumstance it describes. ‘All apples are apples,’ however, hold true from the foundation of the cosmos to its end, in every time and place there is. This was substantive knowledge to Leibniz.  According to Leibniz it is the principle found in such universal knowledge that allowed us to use the senses, rather than the senses being the source of our knowledge. Without pure reason, to Leibniz, sense experience would be worthless; we could never progress in knowledge without the eternal principles of analytic reason, with which we analyse and process this sensory data. The senses are subject to doubt as well; they may all be dreams and fictions, while whether I am dreaming or awake if I think to myself ‘All apples are apples’ the proposition yet holds true, and I know it to be so, whether it occurs to me as I am dreaming, or hallucinating or whatever.
 Sometimes a philosopher like Hume will propound a skepticism that makes us doubt whether we can even know what the philosopher himself is arguing, if he is right and we really know that little. But equally, empiricist like Hume betray the veracity of rationalism: Hume, after all, did not show us movies to teach us, he wrote books. If pure reason is worthless, and, least of mention, matters of the sense are only the avenues of our understanding, how is it we are to learn just by following Hume's path of reason? Wouldn't he do better to show us pictures and images? After all, all reasoning, Hume's reasoning even, comes in logical form, comes in words and not images, the stuff of thought. Hume's very enterprise of reasoning his way into showing reason worthless itself betrays the value of reason. Never mind that it was mostly inductive reason; if logic and pure reason were worthless, wherefore does Hume write, filling hundreds of pages of logical processes? We might say to him that he has an awful lot to say about what must be true, for someone who believes we cannot know the truth. In addition he employs logic and reasons quite extensively, for someone who believes pure reason can give us no substantive truth.
 Leibniz saw quite correctly that, though sense experience is probably essential to human nature, and necessary for us to mature our minds in the first place, it is reason that gives us the perspective and principles to use such experiential sense-data. If I should know that a particular apple is green, and a thousand other data of the daily sights and sounds, without logic, reason and mathematics, by which I process and analyse and organize such data, none of our sciences would be possible, least of all philosophy, but the physical sciences of nature also. Sense-data contains the raw facts of the world, and, nonetheless, its found knowledge comes about when the principles in universal rules of reason are used to process such facts into knowing what we do not perceive, are they things like the centre of the Earth or the nature of the infant cosmos. Without universal principles, are they creative inductions like scientific theories, or the deductive rules of logic, sense data would get us nowhere—add fact to fact all one's life, without rational analysis, without using the tools of the ‘inborn light within us,’ and knowledge would be impossible. I am not so much arguing that was there no sense data there would be in fact knowledge, but only that both are required, that reason conductively deduces through sense-data and sense-data bears its fruit by means of reason, in a two-way process, both sides of which are often essential.
 Psychologists today would no doubt insist that psychology be a discipline separate and distinct from that of philosophy. The mere fact that psychology is thought of as a science sets it apart from philosophy and, at times, makes it quite incompatible with philosophy. Yet psychology and philosophy are bound by history in that it is from philosophy that psychology receives the methods that psychology employs in analysing and evaluating the mind and all that it entails. Psychology owes its existence to most philosophical thinkers including Aristotle, Plato, John Locke, and David Hume. Here, our immediate focus on the particular influences of Rationalism, is specifically focussing on the work of René Descartes and the counterarguments of Emmanuel Kant.
 René Descartes was a very private man and the details of his life are only vaguely known. Born in 1596, he was an intellectually bright child and was enrolled in the College at la Flèche at the age of 10. Some time after graduating at the age of sixteen, Descartes took up residence in the Paris suburb of St. Germain. Here, between periods of seclusion, Descartes observed the workings of a set of mechanical fountain statues built for the Queen. Watching these, he developed an idea that real bodies, animal and human, operate much like these automatautilizing a system of hydraulics and fluids to animate the body and its processes. This would be the basic idea involved in his later physiological theories of the brain and visual perceptivity (Fancher, 1979).
 After moving and becomingly reclusive again, Descartes found himself dissatisfied with the uncertainties of much of the information he had learned in school and afterward. He was pleased with the certainties that mathematics offered, but as of yet there were not many ways to apply math to other disciplines. One morning during these frustrations, Descartes found himself watching a fly on the wall (or so the story goes) and suddenly discovered that he could define the fly’s position using only three numbers: the perpendicular distance of the fly from each wall and from the ceiling. Generalizing from this realization, he discovered that any point in space could be defined in a similar way by measuring their distances from perpendicular lines or planes. These numbers have commonly become known as ‘Cartesian coordinates’ and the perpendicular lines as the x -and y-axes. That discovery led to the development of analytical geometry, the first mathematical blending of algebra and geometry. The discovery of the coordinate plane, alone, is a huge contribution to psychology, for without it, defining the relationship between independent and dependent variables, calculating correlations, doing tests of significance, and other quantitative analysis would not be possible (Fancher, 1979)
 After this discovery, Descartes began to wonder if there were other knowledge areas that could give answers or facts that provide the same amount of certainty as their results made to mathematics. Able to think of none, he proceeded with enumerating the faults of then-current scholarship and ultimately concluded that the best course for him to follow would be to disregard everything he had learned and only accept as ‘truth’ those things that he could determine were correct or valid through his own systematic reasoning. To this end, Descartes formed a method for such reasoning that he believed would offer other disciplines the same amount of certainty afforded by mathematics. This method consisted of four rules, stated briefly they are: (1) To proceed by means of doubt, to take nothing for granted, to avoid bias and prejudgment; (2) its distributive subject matter for which the argument becomes that which are the simplest parts; (3) as to the total proceeding in each related stage soon becomes the simple, and, of course, leading to the more complex; (4) To ‘enumerate’ and review to make sure nothing is missed in the argument, and that as many sources for the correct conclusion as possible may be collated.
 Descartes was sure that this method would provide the mathematical elements needed to produce valid and reliable results in scholarly thinking. The first rule of this method, however, was especially troubling to Descartes. Already plagued with doubt about many other supposed truths, Descartes began to doubt everything until he even doubted that he existed. After a long process of doubting and reasoning, he doubted his existence until he realized the only thing he could no longer doubt was that he doubted. He reasoned that because he could not doubt that he was presently doubting, he must at least exist to be doubting. It is from this doubting, and subsequent realization and affirmation of existence we obtain the oft-quoted ‘I think, therefore I am,’ or ‘Cogito, ergo sum’ (Balz, 1952.) By proving that he existed, Descartes reasoned that he could also prove other things to be logically and rationally true by using the method he created.
 Like the development of analytical geometry, the ideas contained in his methodology constitute a large contribution to the future of psychology in that it is precisely from the principles Descartes laid out in his method that deductive and inductive reasoning developed. What is more important, the introduction of methodology for the precise and systematic evaluation and verification if ideas or supposition was crucial to the development of the field of science, to an over-all picture, for much had been attributed to psychology? Descartes’ method provides the fundamental building blocks of the scientific method that modern science heralds as the marrow core in of all procedural guidelines. We, like Descartes, are satisfied that if all of the rules of the scientific method are followed exactly, the results should be valid and dependable.
 Descartes made yet another important contribution to the future field of psychology immediately after his realization that he did exist. As he made this realization, he also realized that he could be sure that the mind and body were separate from one to conclude, in that I was a thing or substance whose whole essence or nature was only to think, and, to exist does not need space nor of any material thing or body. Thus, it follows that this ego, this mind, this soul, by which I am what I am, is entirely distinct from the body and am easier to know than the latter, and that even if the body were not, the soul would not cease to be all that it now is.
 This was an important distinction at this time, for most of the discourse had concerned the workings of the soul with the assumption that the soul controlled most aspects of the body. It had been supposed that the soul was the seat of all reasoning, thought, memory, and so on, and the animating force within the body. It is not until Descartes that the mind is ascribed with the powers of reasoning, knowledge, and emotion separate from the functioning of the rest of the body. For Descartes, the body functions independently from the mind, however the mind and body can interact to produce varying results in behaviour. Although he does still discuss his mind as part of the soul, what is important is that Descartes uses and continues to develop the concept of the rational, thinking mind for being separate and distinct from the body. This mind-body distinction is obviously an important one for psychology, allowing for the development of much of physiological psychology with cognitive and perceptual psychology, among others.
 This mind/body split led Descartes to make further conclusions about how the brain functioned. His primary concerns was the workings of vision and visual perception. Descartes concluded that, based on a previously discovered ‘truth’ that everything is in motion, light and objects give off tiny vibrations and these vibrations press upon various areas of the eye. This then causes the vibrations to move through the eye to stimulate a series of hollow nerves through which essential brain fluids flow. Much like the automata from St. Germain, Descartes envisioned that these brain fluids flowed through the nerves stimulated to constrict or expand by the vibrations of the objects being viewed so that a sort of stamp was of what was seen was created in the brain. Reasoning that because we have two eyes but only seem to perceive any object we are viewing as singular, he further concluded that there must be a centre in the brain in which the vibrations from both eyes meet to create a singular image. For Descartes, this area was the Pineal gland because it entered the brain and not lateralized like the rest of the brain. It was also here, he concluded, that the soul resided.
 Although much of how Descartes reasoned, the mind to work was incorrect, some basic ideas were fundamental for future work on perception and physiological psychology. Among the important ideas is Descartes’ graphing of the visual field of perception that showed that each eye not only perceives what is directly in front of it, but also receives sense information from the outer field of the opposite eye (essentially that we see much in the left side of our visual field with our right eye and vice versa). Also, though he was wrong about the vibrations and hollow nerve tubes, he was correct in reasoning that there must be some centre in the brain where the images from both eyes are combined into a singular image to be consciously dealt with by the mind.
 Descartes evidently had a profound impact on ways of thinking about the world and that this impact is still seen in much of modern psychology. However, these ideas in and of themselves did little to further the cause of Psychology, for Descartes’ method of ascertaining the truth by reason alone left out an entire realm of discussion that dealt not with how the senses perceived, but what the senses perceived. Indeed, the tenets of rationalism stated that sensory information was likely to be false and unreliable and summarily dismissed it from further discussion. There was a second group of thinkers, however, who viewed sensory information and experiences as the only accurate measurements of and indicators of ‘truth,’ as this group was called the empiricist.
 Basic rationalism teaches of: (1) Don’t trust senses, since they sometimes mislead, knowingly; since the ‘knowledge’ they provide is inferior (because it changes; (2). Reason alone can provide knowledge. Math is the paradigm of real knowledge. (3) There are innate ideas, e.g., Plato’s Forms, or Descartes’ concepts of self, substance, and identity. (4) The self is real and discernable through immediate intellectual intuition (Cogito ergo sum). (5) Moral notions are comfortably grounded in an objective standard external to self -in God, or Form. Basic empirics’ precepts were as of (A) senses is the primary, or only, a source of knowledge of the world. Psychological atomism. (B). Mathematics deals only with relations of ideas (tautologies); gives no knowledge of the world. © No innate ideas (though Berkeley accepts Cartesian self). General or complex ideas are derived by abstraction from simple ones (conceptualism). (D). Hume -there’s no immediate intellectual intuition of self. The concept of ‘Self’ is not supported by sensations either. (E) Hume -no sensations support the notion of necessary connections between causes and effects, or the notion that the future will resemble the past. (F) Hume -‘is,’ that does not imply to ‘ought’ for each their source of morality is feeling.
 Although both of thee schools of thought believed that truth was attainable, they disagreed about the role that the senses played in discovering this truth. The rationalists employed deductive reasoning, reasoning that does not depend on experience to inform it (for example concepts and constructs such as bachelor or death that do not require certain experiences to be understood) to attain truths. The empiricist utilized empirical reasoning, reasoning that depends upon experience or contingent events in the world to inform it (that George Bush, Jr. is president in 2004 cannot be determined by examining the concepts of ‘president’ and ‘George Bush’). This disagreement over which type of reasoning was superior continued until the 1780’s when Emmanuel Kant, a German philosopher, began publishing his most influential works.
 Kant’s work was primarily a reaction against the work of the empiricist David Hume. He found problems with both the empiricist and the rationalists, however. Essentially Kant proposed that neither rationalism nor empiricism were sufficient, or correct, in determining absolute truths for there were truths that neither of these two schools could prove as such by only using inductively and theoretical reasoning. Moreover, both modes of thought contained flaws that allowed two contradictory statements, or autonomies, to both be accepted as true and valid.
 Kant argues that while both rationalism and empiricism assume that obtaining knowledge of how things really are is possible, as opposed to how they seem to us, they overlook the fact that the human mind is limited. The human can experience and imagine only within certain constraints; the human mind has a hand in constructing and shaping our reality as we perceive and think about it. Specifically, these constraints are synthetic and deductively. Synthetic deductive truths, which include location in space and time, causality, experiencing self, thing-ness, and identity, does not depend on experience to be realized but also cannot be arrived at by the same kind of logical reasoning used by the rationalists. Neither of the two schools of thought was equipped to deal with these kinds of truths.
 The solution to this problem, Kant argued, was to understand that the world we experience must be distinguished into two categories -the noumenal, or external world, and the phenomenal, or an internal world. The noumenal world consists of ‘things-in-themselves,’ objects, as they exist in their pure and unfiltered form. However, Kant warns, the noumenal world can never be known directly because once it is perceived by the human mind it passes into the phenomenal world. What humans experience is not the actual world, but a re-creation, an interactive experience, of the world (Fancher, 1979)  In this way, Kant argues that the mind is an active agent in how we perceive and interact with the world; it creates reality just as much as it perceives it.
 Through this argument, Kant creates a melding of the two schools of thought-rationalism and empiricism. He verifies the methods of the empiricists, in his agreement that of all that we perceive, think about, and thus know, is filtered through our senses and experience. Empiricism is complicated however, when Kant also insists that our mind create and interprets experience and ‘reality’ as it perceives it, and therefore rational reasoning must also be employed to ascertain several truths. It is only through combining these two methods that most truths may eventually be realized.
 The extensive contributions of Descartes and the rationalists provided many ideas and distinctions that necessarily predicated Kant’s philosophical works. Especially important was the mind/body distinction and the development of the idea that mind and body could interact with one another. Kant, by arguing that a cohesive and valid science would not be possible unless the conditions of his synthetic deductive reasoning were met, encouraged, if not forced, the melding of the rationalist and empiricist modes of thought into one that allowed for both sensory experiences and reasoning, together, to provide the basis of ‘truth.’ However, perhaps the most important contribution to psychology is that all of this culminated in the new idea that the mind creates reality just as much as it perceives it. This idea paved the way for, indeed, created the need for a more exact study of the mind. With these new ideas in hand, and the previous obstacles to thinking removed, it would be less than a hundred years later that the first experimental psychology labs would be established and psychology would begin to flourish as a science.
 Friedrich Nietzsche is not only one of the most influential philosophers the world has seen, but he is also one of the most controversial. He has influenced the twentieth century thought more than almost any other thinker. In his numerous works, Nietzsche constantly criticizes and restructures the strongly held philosophical and religious beliefs of his time. One such principle that he refutes belongs to his predecessor Rene' Descartes, and concerns the apparent distinction and significance of the human mind over the body. Descartes explains this elaborate theory in his Meditations on First Philosophy, claiming that the mind (the conscious) is the lone essential part of the human essence. On the other hand, Nietzsche stated via his manifestation through which all dynamic contributes are functionally of his distributive order as set further ahead by his work, On the Genealogy of Morality, his beliefs that the body (the unconscious) is key to the human essence. One may find it difficult to decide between these two ideas, for both philosophers pose good arguments on the contradicting sides of this famous dilemma.
 However, by analysing them further, I realize that the qualities of their arguments are only as good as the foundations upon which they are based; one cannot have an understanding of the mind or the body without first having knowledge of the essence of human existence. Consequently, I will prove that the body is superior to the mind by showing that the centre for Nietzsche's ideas, the human essence, is more valid than that of Descartes.
 Descartes' idea of the human essence is based solely on his formed concept of ‘radical doubt.’ He believes the essence of human existence to be simply ‘a thinking thing.’ We must now analyse how he arrived at this conclusion. Descartes is famous for radical doubt, a concept that questions everything, and assumes nothing to be true unless it can be proved so with his idea of ‘clear and distinct perception.’ From this he states that the only thing he can clearly and distinctively perceive is that ‘I exist.’ He concludes that since he ceases to exist when he ceases to think, he can then clearly and distinctively call himself a ‘thinking thing.’ Descartes explains this train of thought when he says: From the fact that I know that I exist, and that while I judge that obviously nothing else belongs to my nature or essence except that I am a thinking thing, I rightly conclude that my essence consists entirely in my being a thinking thing. Although perhaps I have a body that is very closely joined to me, nevertheless, because on the one hand I have a clear and distinct idea of myself, insofar as I am merely a thinking thing and not an extended thing, and because on the other hand I have a distinct idea of a body, insofar as it is merely an extended thing and not a thinking thing, it is certain that I am really distinct from my body, and can exist without it.
 Descartes’ arrival of the human essence as a ‘thinking thing’ in this way is obviously fully based on his beliefs of radical doubt and clear and distinct perception. He bases all of his inferences on other inferences.
 Descartes also devaluates the human body and places the mind at the essence of the human existence based on his concept. Due to his radical doubt, Descartes quickly omits the body and the entire physical world as having any significance because of the simple fact that they can be doubted. He establishes a strong sense of doubt in his senses, because, according to Descartes, one cannot know clearly and distinctly that they are not being deceived into their physical sensations. Descartes thus condemns the significance of the body when he proclaims that it is ‘not a substance endowed with understanding.’ He places the body into the physical, unintelligible realm of his concept of dualism, opposite from the thinking, knowledgeable realm. Descartes now acknowledges the body for being useful only within the limits of ‘moving from one place to another, of taking on various shapes, and so on.’ It is from this condemnation of the body into the physical, unintelligible realm that Descartes further places the mind on a pedestal, and at the essence of human existence. To him the mind is superior because it thinks, which is our essence. He explains this in the indented quote I have already cited, saying that the mind can exist without the body. Analysing things with radical doubt clearly finalizes all of Descartes' ideas.
 Therefore, Descartes' argument is not valid because of the fact that it is solely derived from assumptions. His idea of the superiority of the mind is based on the assumption that humans are thinking things, which it is based on the assumption of clear and distinct perception, which is further based on the assumption that radical doubt is valid. Descartes' entire argument includes the use of clear and distinct perception, a concept that he concocted, to evaluate what is true and what is false. Dubbing something valid when it is absurd based on an assumption, let alone many assumptions. Subsequently, it is false to grant Descartes' ideas any relevance because they are derived by judging things on his basis. Steven J. Wagner, in his essay ‘Descartes's Arguments for Mind-Body Distinctness,’ lends us support, at which this point becomes of us, as of when we are to believe of its good or the contrarieties of bad, that the proponents as gestured by our understanding were by him to say of: ‘Descartes's procedure only makes good sense once we see it as a product of his system. Too much in Descartes depends on things that are far too wrong.’ He explains that Cartesian (Descartes' thinking) dualism and the Cartesian mind can only be supported along Cartesian lines. It requires little intelligence to prove a point when one bases their argument for it on invalid theories of their own fabrication. The superiority of the mind in the human essence, therefore, has not been clearly proven because its ideal is based on Descartes' numerous assumptions.
 Nietzsche's idea of the human essence, on the other hand, clearly holds more validity than Descartes' because it is not based on assumed principles. Nietzsche believes the human essence to be one of the competition, survival and a will to power. Unlike Descartes, Nietzsche's ideal is based on a foundation of facts. He concocts his ideal mostly by observing nature and the world around him. Bertram M. Laing, in his essay ‘The Metaphysics of Nietzsche's Immoralism,’ explains Nietzsche's belief called the ‘organic process,’ whereas the world is ‘a continual distribution and redistribution of force or power.’ Nietzsche, like Freud, attempts to account for the function of consciousness considering the new understanding of unconscious mental functioning. Nietzsche distinguishes between himself and ‘older philosophers’ who do not appreciate the significance of unconscious metal functioning, while Freud distinguishes between the unconscious of philosophers and the unconscious of psychoanalysis. What is missing if the acknowledgement of Nietzsche as philosopher and psychologist whose ideas on unconscious mental functioning have very strong affinities with psychoanalysis, as Freud himself on a number of other occasions, come to acknowledging in a specific and detailed manner an important forerunner of psychoanalysis? Although Freud has stated that Nietzsche’s insights are close to psychoanalysis, very rarely will he state any details regarding the similarities.
 At its present state as a specific individual science the awakening of moral observation has become necessary, and people can no longer be spared the cruel sight of the moral dissecting table and its knives and forceps. For here thee rules that science that asks after the origin and history of the so-called moral sensations. Freud ‘who puts aside all his feelings, even his human sympathy, and concentrates his mental forces on the single aim of performing the operation as skilfully as possible.’ [However it] the unconscious must be assumed to be the general basis of psychical life. The unconscious is the true psychical reality, which in its innermost nature it is very much unknown to us as the reality of the external world, and it is as incompletely presented by the data of consciousness as is the external world by the communications of our sense organs, . . . that apart from conscious there are also unconscious psychical processes.
 Nietzsche goes on to discuss a number of unconscious thoughts, feelings and motivations that are involved I the feeling of pity. Such unconscious motivations are clearly repressed (inadmissible to consciousness), although the analogy of the foot slipping points to what is unconscious but would be admissible to consciousness. As this example to Nietzsche does not make the specific distinction, but his work is filled with explorations of our emotional states that are commonly regarded as selfless and highly moral but which he demonstrate are involved in our self-enjoyment and self-gratification. Our disguised expressions of sexuality and will to power, while unconsciously denying that this is so and assuaging conscience. Nietzsche was interested in ‘the diverse operations of the conscious and the instinctive.’ In a note from 1870 or 1871, he also wrote, though in a different sense than Freud, that ‘all growth in our knowledge arises out of the making conscious of the unconscious.’
Other than the specific distinction between these systems, every major point of Freud’s, both along with and beyond Lipps, had been explicitly discussed by Nietzsche. Nietzsche was aware of the distinction between unconscious processes that were and were not ‘inadmissible to consciousness.’ It is true that he doesn’t always specifically make the distinction, though he is clearly aware of it.
 Nietzsche goes on to a number of unconscious thoughts, feelings and motivations that are involved in the feeling of pity. Such anconeous motivations are clearly repressed (inadmissible to consciousness), least of mention, Nietzsche does not make the distinction, but he writes of both kinds of conscious processes. We call also change one’s mind to that by some early age Nietzsche was interested in ‘the diverse operations of the conscious and the instinctive,’ up to this point he regards conscious and unconscious for their possessives as, ‘subject to different laws of development.’
 He certainly did not believe that there was a realm of ‘the things-in-themselves’ as ‘a metaphor for the chaotic and unknowable true world that lay beyond perception.’ The real world is process and change for Nietzsche, as in his later works there is no ‘unknowable true world.’ For one thing, Nietzsche was attempting to get across the point that there is only one world, not two. And that for Nietzsche, if there is anything we contribute to the world, it is the idea of a ‘thing,’ and in Nietzsche’s words, the psychological origin of the belief in things forbids us to speak of ‘things-in-themselves,’ yet points out that in regard to the distinction between ‘appearance’ and ‘reality,’ and what he repudiates is the distinction between and separation of a merely apparent world and a world of ‘true being.’
 Once, again, we can consider that Nietzsche clearly thought he uncovered some truths regarding the areas into which he had inquired, whether it be the origin of bad conscience or the psychological motivations of the Apostle Paul. Truth is not illusory but it does unavoidably entail perspectivity. For Nietzsche, the apparent world is not cut off from a world of absolute truth. While Nietzsche is quite willing as in his psychological exploration, to draw destinations between ‘deeper’ realities in relation to ‘surface’ appearances, he also argues that on a fundamental level one cannot draw a distinction between a merely apparent world and a perspective-free factual world. The ‘deeper’ realities he discovered cannot be regarded as facts-in-themselves or anything else of the kind that would be free of embeddedness in human schemes, practices, theories, and interpretations, of sortal perspectives seeing and knowing.
 Although Nietzsche calls into question the absolute value of truth, values the illusions (the truthful illusions) of art that ae a stimulant to life, values masks, veils and even the creative lie, he also answers the call of truth. Truth calls to us, tempts us to unveil her. If we have integrity we will say ‘Yes’ to the hardest service, surrounding much that we hold dear, including our wishes ‘not to see . . .  [what]  . . . one does see. When the unveiling takes place to recognize as not truth (or women) in-itself but an appearance that is reality by way of a particular perspective, as one might regard this situation as, among other possibilities an opportunity for the creative play of our interpretive capacities, fo the creating and destroying of play, for a creative sublimation of the will to power. But none of this obviates our capacity to sometimes reach what can be reasonably regarded as truth. What it does involve, is for Nietzsche ‘neither a noumenal realm of adjudication for competing truth claims, and perhaps what is most important, Nietzsche introduces the notion that truth is a kind of human practice. This entails ‘local pragmatic truth, truths as good as though Nietzsche does posit transhistorical truth claims given as his claim regarding the will to power. Nietzsche is concerned with what corresponds to or fits the facts, but such facts are not established without a human contribution, without interpretation. Of course, for those for whom the tern ‘fact’ should entail a ‘halt before the factum brutum,’ there may be an objection to the use of such terms as ‘fact, reality,’ and so forth, in such a context.
 Nietzsche observes society as a barbaric, predatory world that he separates it into two groups: one having ‘slave morality,’ and the other ‘master morality.’ Those who possess master morality, or noble morality, are the ones who live their lives instinctively by trying to achieve heightened power, often at the expense of others. These people, according to Nietzsche, he, are the active and productive members of society. They exude power and confidence, and prioritize success over popularity. They are the ones who gain the power in the ‘organic process.’ Nietzsche preaches for people to have this kind of morality, for he sees this as ‘good.’  On the other hand, those who possess slave morality are the ones who do not act instinctively and thus are weak. Their weakness is apparent by observing their lack of productivity and success. They became clever to compensate for not being powerful, doing things like congregating for chances of greater defence. These people, according to Nietzsche, developed ‘resentment’ toward their superiors' power. Nietzsche thus calls them ‘the regression of humankind,’ because their morality develops out of hatred and a denial of our bodily instincts. The human essence, therefore, is one of some desires for power and success. Nietzsche cleverly legitimizes this claim  by comparing it with the `survival of the fittest' aspects of nature. ‘Beasts of Prey’ hold the qualities of master morality, for they achieve their goals instinctively at the expense of their prey. They do what is needed for them to survive. Lambs, the prey, are equal to those included in Nietzsche's slave morality because they are weak, and congregate in herds for protection. The Beasts of Prey are obviously the ones who survive, so Nietzsche believes that we should strive to act instinctively like them. Rather than following the intimate steps that gaiting from Descartes' would lead by some trivial reason, it is clear that Nietzsche based his concoction of the human essence mostly on irrefutable observations. In this way his idea surpasses Descartes' in relevance and validity, thus giving him clear ground to employ this ideal in proving the superiority of the body.
 Finally, Nietzsche uses this valid assertion of the human essence to prove that the body is essential to the human existence than the mind. Nietzsche argues that since the human essence is based on a predatory competition necessary in the ‘organic process’ of the world, the body is more important than the mind. Instinct, he says, is rooted in the body that we are given. Thus our bodies define who we are because they determine to what morality, masters or slave, we cohere. Nietzsche believes that one's placement within these categories is decided at birth as an unalterable ‘assignment’ determined by the genealogy of a person's morals. Our bodies determine whether we act according to our natural instincts for success and the will of power (master morality), or if we turn away from them (mutualist morality). These bodily instincts are the key element to our existence, for they completely govern our personalities. By analysing the Beasts of Prey argument again, it is clear that the lambs were born into their existence as preemptively instinctual, and as well as, primitively defensive from which is in as much as ado about its own obviousness for only being duly given to the physically structured consistency. The bodies of birds have also held to an estranged dissimulation, as of their unmannered instinct. It is likewise that this substantiates the body and is therefore the principal element of our existence. It is the difference between eating, and getting eaten, that Bertram M. Laing describes Nietzsche's ‘body’ when she calls it ‘the source of all inspiration; the power that breathes or speaks through one is not an alien deity, but the self, the man as he really is.’ The body, then, is superior to the mind, because it holds our natural instincts that fully determine who we are and how we will fare in the ‘organic process’ of our existence.
 Nietzsche writes: ‘The evidence of the body reveals itself of a tremendous multiplicity,’ Also, ‘Suppose all unity were unity only as an organization? But the thing in which we believe was only invented as a foundation for the various attributes. Similarly: ‘The ‘subject’ is the fiction that many similar states in us are the effect of one substratum.’ Also, for Nietzsche there is no ‘I’ which thinks as a separate entity from the relations which persons have to the world in general. Nietzsche denies that one can suppose any inner thing are from its expressions in relationships. Unity can be attained to a degree, and such unity is highly valued by Nietzsche. But there is no perfect unity through self-creation nor one fixed true self, conscious or unconscious, waiting to be uncovered. And the structure of any ruling unity may at the same time be open to creative self-conflict and possible transformation -: If we are to ‘become who will open ourselves to ‘unremitting transformation -: you must, within a short space of time, pass though and throughout many individuals. The means are unremitting struggles.’ If we allow ourselves to have access to, and develop and utilize, more affects and more eyes, different eyes, we may be on the way to passing though and throughout many individuals. Such possibilities may be both potentially enriching and dangerous.
 Had Wittgenstein ever had at any time feel to have to do with to write about himself, this apparently most ‘intellectuals’ of philosophers might have said: I have always thought with my whole body and my whole life. I do not know what purely intellectual problems are. You know these things by way of thinking, yet your thought is not your experience but the reverberation of the experience of others, as your room trembles when a carriage passes. I am sitting in that carriage, and as often, I am the carriage.
 Although written by Nietzsche, Wittgenstein’s work is none the less suffused with authentic pathos, and it will be seen as an integral pat of the tragically self-destructive design of European thought.
 In the First Meditation, Rene Descartes is to bring of a certain state, the question what he knows. He convinces himself that his senses cannot be trusted and that all his experiences may be nothing more than mere dreams. Descartes finally concludes that he may not know anything, not even the fact that he has a physical body
 His Second Meditation focuses on the finding, in at least, of a single truth, or the intuitive certainty under which he can hold onto. In his quest for this certainty, Descartes rejects ‘whatever admits of the least doubt, just as if [he] found it to be wholly false.’ He even concedes perhaps ‘that nothing is.’ But Descartes is not so easily defeated. He convinces himself that he exists as a thing that thinks, in other words, a ‘thinking thing.’
 How does Descartes reach such an unyielding conclusion? He first proves that despite all his uncertainties, he actually exists. His notion that all physical objects do not exist precludes him from having a body to prove his existence. Instead, Descartes argues that due to the very fact that he has these notions prove that ‘I’ exist. ‘But if I did convince myself of anything, I must have existed.’ He argues that even if deceived by and all-power being then he must also exist because, ‘[the deceiver] will never bring it about that, at the time of thinking that I am something, I am in fact nothing.’ Thus Descartes concludes that ‘I am’, ‘I exist’ is necessarily true whenever he conceives it in his head.
 But what does Descartes mean by his expressing gesture of ‘I-ness’, of course, as might be expected, it was meant for himself. It certainly cannot be a body since he believes all physical objects to be mere illusions. Without the body, there can be no such things as nutrition, location motion or sensation. The only immovable attribute he can find that does not require his physical body is his consciousness or experience. He goes far to say that ‘maybe, if I wholly ceased from experiencing, I should at once wholly ceases to be.’ Furthermore, he says that ‘‘I am’ precisely taken refers only to a conscious being; that is a mind, a soul, an intellect, a reason.’ It is this consciousness that allows him see what is necessarily true. He argues that physical objects and attributes are not really perceived by the senses, but only by intellect and by being understood. Descartes concludes his argument by suggesting that it be as obviously perceived by his own mind through intellect and understanding. Thus he proves he knows that he exists of a thinking thing that experiences.
 There are many different points in Descartes’ arguments. Some are more powerful than others but I believe his construct of an all-powerful deceiver is a pervasive one. He uses the evil spirit argument quite well to prove his own existence. I think where he fails adequately to defend his argument is proving that he is a being of consciousness and thus being able to think. For the remainder of this report, I will assume the existence of an evil spirit that deceives him.
 He successfully defends that even if an evil spirit were deceiving him, he must undoubtedly exists. I agree with Descartes because if he did not exist, there would be nothing to deceive. So, if there is an evil spirit out to deceive him, he must exist. I agree that he has proven that he is at least a ‘thing’ but not yet of a ‘thinking thing.’
 This brings us to the question of what does it mean to think? Descartes firmly believes that he is ‘a being that doubts, understands, asserts, denies, is willing, is unwilling; further that has sense and imagination.’ He asks the following rhetorical questions to build support his argument: ‘How can any of these things be less of a fact than my existence? Are there any in these of something distinct from consciousness? Can any of them be called a separate thing from myself?’ What Descartes fails to address is that perhaps the evil spirit tricks him into thinking that he has doubts, of which he understands and so forth. What and then? Does he still know he exists? Yes. Is he still a being with consciousness? Perhaps. Is he a thinking thing? Definitely not.
 We already know that we can defend existence with the presence of the evil spirit as described earlier in this paper. He may or may not be a being of consciousness because he may be deceived of the thoughts that lead him to believe that he is conscious. But one might argue that even if he has been deceived that he is conscious then he is. Consequently, I will continue within a framed mind that any assumption that he is conscious being of, sets, least of mention, onto their indirective crystallized assumptions, as sharply as not for a thinking thing. To be the thinking thing that he claims at the end of the meditation would imply that he can perceive by intellect and understanding. However, the evil spirit has deceived him on those matters. He has neither the intellect nor the capacity to understand and thus to perceive. Furthermore, by inverting his argument ‘that nothing is more easily or manifestly perceptible to me than my own mind’ we can suggest that since he cannot perceive his own mind, he cannot exist.
 But this raises a contradiction, has already been stated that his existence has been defended in the presence of an evil spirit. So is my last assertion invalid? Indeed it is because I have assumed that the mind and therefore existence can only be perceived through intellect and understanding as Descartes described. However, the mind need not be perceived by intellect nor understanding, it may be perceived due to deception caused by the evil spirit, thereby solving the contradiction. So, Descartes perception that he has intellect and understanding is caused by the evil spirit therefore he does not think.
 What of consciousness? I have to reassume, if not for the moment through which time is an essential fraction for being humanly conscious. Some may argue that consciousness itself leads to thinking for consciousness cannot be without thinking. But just as I eluded sooner than expected, the reasons for believing he is conscious may be caused by the evil spirit. By Descartes’ own definition, a conscious being is one who doubts, understands and so on. However, if those doubts and understanding are not his own, but rather caused by an evil spirit, he does not really have those thoughts and feelings. And without those thoughts and feelings, he cannot be a conscious being. If he is not a conscious being, then he obviously cannot be a thinking thing. In short, the evil spirit can deceive Descartes into thinking he has consciousness when in fact he does not therefore he does not think.
 So although we agree that Descartes can convince himself that ‘I am’, ‘I exist’, I do not agree that he has adequately shown that he is a thinking thing. I have shown that if the evil spirit deceives Descartes’ on perceived notion that he doubts, understands and so on, then Descartes has a false impression that he is conscious and therefore has a false impression about his ability to think. If the evil sprit does exist, Descartes can prove he exists but not as a thinking thing.
 Descartes' human commitment to innate ideas places him in a rationalist tradition tracing back to Plato. Knowledge of the nature of reality derives from ideas of the intellect, not the senses. An important part of metaphysical inquiry therefore involves learning to think with the intellect. The allegory of the cave portrays this rationalist theme about epistemically distinct worlds. Plato likens what the senses reveal to shadowy imagery on the wall of a poorly lit cave -to brain images of mere figurine beings; he likens what the intellect reveals to a world of fully real beings illuminated by mental capacities. The metaphor aptly depicts our epistemic predicament, on Descartes' own doctrines. An important function of his methods is to help would-be Knowers redirect their attention from the confused imagery of the senses, to the luminous world of the intellect's clear and distinct ideas.
 Further comparisons arise with Plato's doctrine of recollection. The Fifth Meditation comments of occupying -of having applied Cartesian methodology, thereby discovering innate truths within: ‘on first discovering them it seems that I am not so much learning something new as remembering before what I knew. Elsewhere Descartes adds, of innate truths: We come to know them by the power of our own native intelligence, without any sensory-data to go through. All geometrical truths are of this sort -not just the most obvious ones, but all the others, however abstruse they may appear. Hence, according to Plato, Socrates asks a slave boy about the elements of geometry and thereby makes the boy able to dig out certain truths from his own mind that he had not previously recognized were there, thus attempting to establish the doctrine of reminiscence. Our knowledge of God is of this sort.
 The famous wax thought experiment of the Second Meditation is supposed to illustrate (among other things) of a procedural layout, from which it gives by saying it has underlying implications for being innate. The thought experiment purports to help the mediator achieve a purely mental recapitulation. Much more of an easily apprehending mode for it is the innate idea of body. According to Descartes, our minds come stocked with a variety of intellectual concepts -ideas whose content derives solely from the nature of the mind. This storehouse includes ideas in mathematics (e.g., number, line, a triangle), logic (e.g., contradiction, necessity), and metaphysics (e.g., identity, substance, causality). Interestingly, Descartes holds that even our sensory ideas involve innate content. On his understanding of the new mechanical physics, bodies have no real properties resembling our sensory ideas of colours, sounds, tastes, and the like, thus implying that the contentual ideas are drawn to bear out in the mind. Unlike purely intellectual concepts, however, the formation of these sensory ideas depends on sensory stimulation. I suggest that on Descartes' official doctrine, ideas are innate insofar as their content derives from the nature of the mind alone, as opposed to deriving from sense experience. This characterization allows that both intellectual and sensory concepts draw on native resources, though not to the same extent.
 Though the subject of rationalism in Descartes' epistemology deserves careful attention, the present essay generally focuses on Descartes' efforts to achieve indefeasible Knowledge. Relatively little attention is given to his interesting doctrines of innateness, or, more generally, his ontology of thought.
 Scholars have established many relations of Descartes' philosophy to medieval sources, as antidote to the supposition that the history of philosophy begins de novo with Descartes, though sometimes obscuring the difference between Cartesian, hence modern, philosophy and earlier thought. From the first appearance of the Cartesian philosophy, there was noted a remarkable similarity, especially respecting the Cogito, between Descartes and Augustine, and Arnauld then began a controversy in the fourth set of Objections to the Meditations 1, on which much has been written, especially in the twentieth century, the question whether Descartes' Cogito is or is not original to him. Nothing needs to be added to the side of kinship, nor to the side of difference in this controversy, than the two sides need to be drawn together to shed some light on the logic of the Cogito in both St. Augustine and Descartes, and the movement in thought from one to the other.
 As any fair reading to the texts would show, both Descartes and Augustine find in the Cogito a deliverance from skepticism, then a movement from the Cogito to the spirituality of the soul, finally to an argument for God's existence. Yet there are also important differences, on the face of it, but as you are aware, it is, especially in the movement from the Cogito that knowledge of God's existence. Though both Augustine and Descartes required that we enter of ourselves into knowing that God exists, Augustine moves through eternal, immutable truths, such as the truths of mathematics, for him the standard whereby the human mind judges and higher than the temporal, changing human subject, to the unchangeable substance, God. There is present in Descartes, opposing such a proof, a theological presupposition of God's freedom and omnipotence extending as well to essences or ‘eternal truths’ as to existence, to the possibility as to reality, to truth as to being. This is the remarkable doctrine of the ‘creation of eternal truths,’ revealed by him directly in correspondence with Mersenne, later in the replies to the fifth and sixth set of objections to the Meditations, which appears obliquely in his published treatises in the extension of methodic doubt to the truths of mathematics and in the rejection of final causes. The Augustinian proof, since it moves through eternal truths in themselves dubitable acquired of a guarantee of the Divine veracity, would not for Descartes be valid.
 Descartes' movement to the knowledge of God from the Cogito is through the idea of God, eternal, Infinite, immutable, omniscient, omnipotent, Creator of all things, also to have been regarded for being that whose celestial totality exists of itself in reasons that speak for saying, ‘just as it should be.’ The Law Maker, the idea, is, perhaps, more than is less or fewer than should be, is not, for which is born the thoughts that have power of neither additional nor supplementary attributions. That its essential essence of an idea is born infinitely contentual of its thought and is addressed through one who is imperfect, limited yet dependent. It is the only idea that is not by his attained upright position, so to speak, and is not brought forth through himself. For all other ideas are not very content by its superior realms to his thoughts. Yet he knows this idea not by a via negative, but positively, clearly and distinctly. That the Cartesian philosophy may come upon in the Cogito movement in this manner to knowledge of the existence of God, whether as in the Meditations to the cause of such an idea of God, or as in the Principles of Philosophy through an ontological argument, is foreign to the Augustinian philosophy. Though it is true that for Augustine as for Descartes the soul does have within itself an idea of God, still because of its weak and fallen nature, its mutability and finitude, it is by faith that it initially grasps the true idea of God as Trinity. The first admonition of Augustine, credo ut intelligas, is violated in the Cartesian procedure that begins solely with the ‘natural light’ of reason.
 Scholars have established many relations of Descartes' philosophy to medieval sources, as antidote to the supposition that the history of philosophy begins de novo with Descartes, though sometimes obscuring the difference between Cartesian, hence modern, philosophy and earlier thought. From the first appearance of the Cartesian philosophy, there was noted a remarkable similarity, especially respecting the Cogito, between Descartes and Augustine, and Arnauld then began a controversy in the fourth set of Objections to the Meditations 1, on which much has been written, especially in the twentieth century, the question whether Descartes' Cogito is or is not original to him. Nothing needs to be added to the side of kinship, nor to the side of difference in this controversy; rather the two sides need to be drawn together to shed some light on the logic of the Cogito in both St. Augustine and Descartes, and the movement in thought from one to the other. There is then this important difference in the Augustinian and Cartesian Cogito detected in the movement to the existence of God: in Augustine, it is a finding of exemplary ideas having a universality at variances with their being of a particular subject, a movement from a changeable subject to its underlying universality; the Cogito of Descartes is already apart from change, finds itself with universal ideas of which it feels perfectly competent to be the cause. For Descartes, only the idea of a perfect being surpasses it and gives it pauses, whereas Augustine's Cogito is not competent even to the ideas of mathematical truths.
 Both forms of the Cogito are contra Academicos, and both forms affirm to the spirituality of the soul: As two rely upon their relationships. It ought not to be thought that the Augustinian or Cartesian argument against skepticism is merely destructive, that si fallor, sum or ego sum si me fallit simply refutes the sceptical position. Rather, the Cogito shows what the real error of skepticism is: it assumes the separation of thinking from its object; and in the same act it both reveals the fundamental ground of certainty and gives to thought a content appropriately its own. Mind thus remaining true to itself knows itself as a spiritual being and the content appropriate to it also as immaterial or idea. In these two respects the Cartesian Cogito and the Augustinian are in the closest harmony. But to this it must be noted that whereas for Augustine the Cogito occurs as part of the movement to scientia of matters revealed and held absolutely by faith, a movement that begins with a presupposition, the absolute standpoint of revealed truth, for Descartes the Cogito occurs as the absolute beginning. The Cartesian Cogito is more than a refutation of skepticism and an assertion of the pure spirituality of the soul; it is further the affirmation that nothing is acceptable to think which is not as clear and distinct as thought itself. As such, the Cartesian Cogito can ably give to the movement through which are the ontological arguments for God's existence, justly caused for only a Cogito is without a presupposition that makes possible the ultimate demand of argumentively conducted deductions, and, within the mind, appealing to nothing external. Finding within thought an idea of God to which necessary existence pertains just as clearly and distinctly as existence pertains to the thinking subject, its demand is fulfilled.
 Certain differences in the philosophical standpoints of Descartes and St. Augustine are exemplified and take their origin in this difference in the Cogito as it occurs in the one and in the other. For both, knowledge through the senses is dubitable: in St. Augustine, because it is not immediate, for Descartes because its falsity is conceivable. Again in both there is a knowledge that is absolutely certain: For St. Augustine, it is because it is immediate, not by representation, for Descartes because its falsity is inconceivable. Thus, for Augustine ‘eternal truths,’ since unchangeable and immutable, are indubitable, whereas for Descartes, their truth is not immediate, but mediated through the knowledge of God's existence, and hence thought cannot by its own measure derive the truth of God's existence from them, their truth from God's existence.
 It would be wrong to think of the Cartesian beginning with no other presupposition than thought alone as apart from all relation to the theology given more comprehensively in St. Augustine. It is rather the beginning of the philosophical reconstruction of that theology in finite subjectivity, that is, from the human standpoint. The Divine Revelations that must, with Augustine, be explicated at the outset, that the doctrine of the Trinity might be grasped as the fundamental doctrine of Christian faith, has by the seventeenth century informed human reason itself, the purgatio mentis has been effected. Modern philosophy, after the Christianization of those one thousand years has had its effect, takes into the finding that any presupposition superfluous and unworthy of the Divine Revelation itself, not through pride, but that the truth might reveal itself now as true.
 Descartes' doctrine of the ‘creation of eternal truths,’ to which attention has been drawn, is a direct consequence of theological wisdom endeavouring to take seriously in its conception of Nature the Christian doctrine of Creation and the Divine Incarnation. Not content simply to grasp the ideal exemplars of nature, and their relation to God in the Divine Word, there is found in modern philosophy at least implicitly the need to know the activity of God in Creation. If at first this appears in Descartes as an unbalanced stress on God's freedom as purely volitional activity, as might be said of his first enunciation of the position in 1630 (this was the criticism of Mersenne), the position was tempered in the Meditations where the pure volitional activity of the genius malignus gives way to the idea of God, infinite power, infinite thought, infinite goodness.
 An ontological argument, which is not found in Augustine, cannot fittingly be found there, where there is a Cogito and hence a grasp of a finite thinking about God, and yet a prior presupposition that cannot allow the Cogito its ultimate development. As the ontological argument occurs in Anselm, it occurs without a Cogito and hence admits of the further criticism of St. Thomas that the finite subjective element is an impediment and an element of which the concept of God must be divested, lest the concept be something merely in thought. Yet it is the most Trinitarian of arguments, as Anselm knew. A long development in making the belief in God one's own must occur from the thirteenth century to the dawn of modern philosophy before an ontological argument can be grasped as properly one's own. There is then this important
Difference in the Augustinian and Cartesian Cogito detected in the movement to the existence of God: in Augustine, it is a finding of exemplary ideas having a universality at variances with their being of a particular subject, a movement from a changeable subject to its underlying
Universality, the Cogito of Descartes is already apart from change, finds itself with universal ideas of which it feels perfectly competent to be the cause. For Descartes, only the idea of a perfect being surpasses it and gives it pauses, whereas Augustine's Cogito is not competent even to the ideas of mathematical truths.
 May it not to be thought that the Augustinian or Cartesian argument against skepticism is merely destructive, that si fallor, sum or ego sum si me fallit simply refutes the sceptical position. Rather, the Cogito shows what the real error of skepticism is: it assumes the separation of thinking from its object, and in the same act it both reveals the fundamental ground of certainty and gives to thought a content appropriately its own. Mind thus remaining true to itself knows itself as a spiritual being and the content appropriate to it also as immaterial or idea.
 Certain differences in the philosophical standpoints of Descartes and St. Augustine are exemplified and take their origin in this difference in the Cogito as it occurs in the one and in the other. For both, knowledge through the senses is dubitable: in St. Augustine, because it is not immediate, for Descartes because its falsity is conceivable. Again in both there is a knowledge that is absolutely certain: for St. Augustine, it is because it is immediate and not by representation, for Descartes because its falsity is inconceivable. Thus, for Augustine ‘eternal truths,’ since unchangeable and immutable, are indubitable, whereas for Descartes, their truth is not immediate, but mediated through the knowledge of God's existence, and hence thought cannot by its own measure derive the truth of God's existence from them, than their truth from God's existence.
 It would be wrong to think of the Cartesian beginning with no other presupposition than thought alone as apart from all relation to the theology given more comprehensively in St. Augustine. It is rather the beginning of the philosophical reconstruction of that theology from in the finite subjectivity, that is, from the human standpoint. The Divine Revelation that must, with Augustine, be explicated at the outset, that the doctrine of the Trinity might be grasped as the fundamental doctrine of Christian faith, has by the seventeenth century informed human reason itself; the purgatio mentis has been effected. Modern philosophy, after the Christianization of those one thousand years has had its effect, next to its forgiving truth, finding any presupposition superfluous and unworthy of the Divine Revelation itself, not through pride, but that the truth might reveal itself now as true.
 Descartes' doctrine of the ‘creation of eternal truths,’ to which attention has been drawn, is a direct consequence of theological wisdom endeavouring to take seriously in its conception of Nature the Christian doctrine of Creation and the Divine Incarnation. Not content simply to grasp the ideal exemplars of nature, and their relation to God in the Divine Word, there is found in modern philosophy at least implicitly the need to know the activity of God in Creation. If at first this appears in Descartes as an unbalanced stress on God's freedom as purely volitional activity, as might be said of his first enunciation of the position in 1630, the position was temper in the Meditations where the pure volitional activeness of the ‘sense datum maleficent’ that gives the ways upon which we view, as in principle to the idea of God, infinite power, infinite thought, infinite goodness.
 An ontological argument, which is not found in Augustine, cannot fittingly be found there, where there is a Cogito and hence a grasp of a finite thinking about God, and yet a prior presupposition that cannot allow the Cogito its ultimate development. As the ontological argument occurs in Anselm, it occurs without a Cogito and hence admits of the further criticism of St. Thomas that the finite subjective element is an impediment and an element of which the concept of God must be divested, least the concepts be something merely in thought. Yet it is the most Trinitarian of arguments, as Anselm knew. A long development in making the belief in God one's own must occur from the thirteenth century to the dawn of modern philosophy before an ontological argument can be grasped as properly one's own.
 Descartes' movement to the knowledge of God from the Cogito is through the idea of God, eternal, infinite, immutable, omniscient, omnipotent, Creator of all things, an idea to which thought has power of neither to any additional substantive attributions. As to an idea, from which is infinitely to  surpass all contentual implications that are representationally obtainable of their thoughts are inclined of being ingested for oneself, imperfect, limited, dependent. It is the only idea that is not his by right, so to speak, not begotten by himself, for all other ideas are not contentually superior to his thought. Yet he knows this idea not by a via negative, but positively, clearly and distinctly. That the Cartesian philosophy can in finding the Cogito movement in this manner, the knowledge sustained through the existence of God, whether as in the Meditations to the cause of such an idea of God, or as in the Principles of Philosophy through an ontological argument, is foreign to the Augustinian philosophy. Though it is true that for Augustine as for Descartes the soul does have within itself an idea of God, still because of its weak and fallen nature, its mutability and finitude, it is by faith that it initially grasps the true idea of God as Trinity. The first admonition of Augustine, credo ut intelligas, may be violated in the Cartesian procedure that begins solely with the ‘natural light’ of reason.
 There is then this important difference in the Augustinian and Cartesian Cogito detected in the movement to the existence of God: in Augustine, it is a finding of exemplary ideas having a universality at variances with their being of a particular subject, a movement from a changeable subject to its underlying universality; the Cogito of Descartes is already apart from change, finds itself with universal ideas of which it feels perfectly competent to be the cause. For Descartes, only the idea of a perfect being surpasses it and gives it pauses, whereas Augustine's Cogito is not competent even to the ideas of mathematical truths.
 It would be wrong to think of the Cartesian beginning with no other presupposition than thought alone as apart from all relation to the theology given more comprehensively in St. Augustine. It is rather the beginning of the philosophical reconstruction of that theology in finite subjectivity, that is, from the human standpoint. The Divine Revelations that must, with Augustine, be explicated upon the onset, that the doctrine of the Trinity might be grasped as the fundamental doctrine of Christian faith, and has by the seventeenth century has let known to human reason, that the purgatio mentis has been cause to occur. Modern philosophy, after the Christianization of those of one thousand years has by its effect, that without there be to proceeding issue that for the chance of subjectivity, it might now be completely in the finding, among other things, the needed location for any given presumptuous excessiveness and the actualized contemptibility of the Divine Reevaluations, not through any congratulatory pride, but that the truth might reveal itself as a possible presents, and every bit as necessarily true.
 An ontological argument, which is not found in Augustine, cannot fittingly be found there, where there is a Cogito and hence a grasp of a finite thinking about God, and yet a prior presupposition that cannot allow the Cogito its ultimate development. As the ontological argument occurs in Anselm, it occurs without a Cogito and hence admits of the further criticism of St. Thomas that the finite subjective element is an impediment and an element of which the concept of God must be divested, lest the concept be something merely in thought. Yet it is the most Trinitarian of arguments, as Anselm knew. A long development in making the belief in God one's own must occur from the thirteenth century to the dawn of modern philosophy before an ontological argument can be grasped as properly one's own.
 As the 19th century progressed, the problem of the relationship of mind to brain became ever more pressing. Indeed, so deep was the concern with mind/brain relations that it is difficult to find a systematic text written after 1860 that does not contain a discussion of this issue. Usually, this directly reflected two major developments that converged to impress philosophers and psychologists with the centrality of the mind/brain problem. The first of these involved progress in understanding the localization of cerebral function, based on the idea that the brain serves as the organ of mind. The second involved a growing familiarity with the thesis that mental events -beliefs, mental suggestions, mesmeric trance states, psychic traumas and the like -sometimes cause radical alterations in the state of the body. This change occurred as progress was made in understanding the nature of functional nervous disorders. Before proceeding further, we will briefly describe some major mind/brain perspectives articulated in response to these trends.
 Although the theories of mind/brain relationship prevalent in the 19th century -epiphenomenalism, interactionism, dual-aspect monism, and mind stuff -were formulated in science, they, like their predecessors, were attempts to deal with the metaphysical complexities of the Cartesian impasse. It is not surprising, therefore, that these views evolved for the most part as variations on themes already addressed.
 Prince was born in Boston and educated at Boston Latin, Harvard College, and Harvard Medical School. Inspired by the work of Chariot and Janet on hysteria, Liébeault and Bernheim on suggestion, Gurney on the hypnotic induction of dissociation, and James on automatic writing, Prince entered early upon the study of conscious and unconscious mental phenomena that was to become his life's work. Indeed, while he was still a medical student, he won the Boylston Prize for his graduation thesis, a treatise that eventually formed the core of The Nature of Mind and Human Automatism.
 Like Mind and Human Automatism, Prince concerned himself with justifying the intuitive belief that our thoughts have something to do with the production of our actions. ‘No amount of reasoning,’ he wrote, ‘can argue me out of the belief that I drink this water because I am thirsty.’ After rejecting parallelism for being at variances with this intuition, Prince presented the classic formulation of the mind-stuff metaphysic: ‘instead of there being one substance with two properties or 'aspects,' -mind and motion, -there is one substance, mind; and the other apparent property, motion, is only the way in which this real substance, mind, is apprehended by a second organism: only the sensations of, or effect upon, the second organism, when acted upon (ideally) by the real substance, mind.’ For Prince, in other words, the psychical monism of mind-stuff constituted a modern form of immaterialism.
 Like Prince, William James could never shake his conviction in the efficacy of mind, yet, is there to be some parallelled efficaciousness with Hodgson. Who during an early stage, exerted an influence over the development of James's thought. Even so, is there of any case that neither by him, who couldn’t escape from his belief in the reality and the efficacy of the brain. In 1890, when The Principles of Psychology was finally published, James devoted two chapters to the analysis and critique of contemporary mind/brain views, one to the automaton theory and another to the mind-stuff theory. Both chapters present extensive discussions of reasons for and against the views under analysis. The reader proceeding through the systematic dismantling of each of these views expects James, at any moment, to produce his own brilliant synthesis. Instead, however, even the redoubtable James, like many of those who had preceded him, found him confounded by the Cartesian impasse: ‘What shall we do? Many would find relief at this point in celebrating the mystery of the Unknowable and the 'awe' which we should feel at having such a principle to take final charge of our perplexities. Others would rejoice that the finite and separatist view of things with which we started with had, at last developed its contradictions, and was more or less to lead us dialectically upwards to some 'higher synthesis' in which inconsistencies cease from troubling and logic is at rest. It may be a constitutional infirmity, but I can take no comfort in such devices for making a luxury of intellectual defeat. They are but spiritual chloroform. Better live on the ragged edge, better gnaw the file forever’
 James's ‘solution’ is to opt for a provisional and pragmatic empirical parallelism of the sort to which many psychologists still subscribe. The ‘simplest psycho-physic formula,’ he writes, ‘and the last word of a psychology that contents itself with verifiable laws, and seeks only to be clear, and to avoid unsafe hypotheses’ would be a ‘blank unmediated correspondence, term for term, of the succession of states of consciousness with the succession of total brain processes. . . .’ Beyond that, James suggests that we are unable to go at present without leaving the precincts of empirical science.
 As the 19th century progressed, the problem of the relationship of mind to brain became especially acute as physiologists and psychologists began to focus on the nature and localization of cerebral function. In a diffuse and general way, the idea of functional localization had been available since antiquity. A notion of ‘soul’ globally related to the brain, for example, can be found in the work of Pythagoras, Hippocrates, Plato, Erisistratus, and Galen, among others. The pneumatic physiologists of the middle ages thought that mental capacities were located in the fluid of the ventricles. As belief in animal spirits died, however, so also did we give verification about any contradictory ventricularistic findings that would supplement each hypothesis made, and by 1784, when Jiri Prochaska published his de functionibus systematic nervosi, interest had shifted to the brain stem and cerebrum.
 Despite these early views, the doctrine of functional localization proper, that the notion that specific mental processes are correlated with discrete regions of the brain and the attempt to establish localization by means of empirical observations were essentially 19th century achievement. The first critical steps toward those ends can be traced to the work of Franz Josef Gall (1758 -1828). Gall  was born in Baden and studied medicine at Strasbourg and Vienna, where he received his degree in 1785. Impressed as a child by apparent correlations between unusual talents in his friends and striking variations in facial or cranial appearance, Gall set out to evolve a new cranioscopic method of localizing mental faculties. His first public lectures on a cranioscopy date from around 1796. Unfortunately, his lectures almost immediately aroused opposition on the grounds of his presumed materialism, and in 1805, he was forced to leave Vienna. After two years of travel, he arrived in Paris accompanied by his colleague, Johann Gaspar Spurzheim (1776-1832). In 1810, Gall and Spurzheim published the first volume of the Anatomie et Physiologie du système nerveux en général, Gall's most important contribution to neuroanatomy and the first major statement of his cranioscopy.
 The essence of Gall's method of localization lay in correlating variations in character with variations in external craniological signs. The validity of this approach depended on three critical assumptions: that the size and shape of the cranium reflected the size and shape of the underlying portions of the cerebrum that mental abilities were innate and fixed, and that the relative level of development of an innate ability was a reflection of the inherited size of its cerebral organ. On these assumptions, an observed correlation between a particularly well developed ability and a particularly prominent area of the cranium could be interpreted as evidence of the functional localization of that ability in the correlative portion of the cerebrum.
 While Gall's correlational approach was eventually abandoned in favour of experiment, his conception of fixed, innate faculties replaced by a dynamic, evolutionary view of mental development, and his pivotal assumption concerning the relationship of brain to cranial conformation rejected, it would be a serious error to underestimate his importance in the history of functional localization. Gall's assumptions may have been flawed and his followers may have taken his ideas to dogmatic extremes, as, it is nonetheless a problem that nothing is wrong with his scientific logic or with the rigorous empiricism of his attempt to correlate observable talents with what he believed to be observable indices of the brain.
 Indeed, it was Gall who lay the foundations for the biologically based, functional psychology that was soon to follow. In postulating a set of innate, mental traits inherited through the form of the cerebral organ, he moved away from the extreme tabula rasa view of sensationalists such as Condillac. For the normative and exclusively intellectual faculties of the sensationalists, Gall attempted to substitute faculties defined about everyday activities of daily life that were adaptive in the surrounding environment and that varied between individuals and between species. For speculation concerning both the classification of functions and appropriate anatomical units, he substituted objective observation.
 Even Gall's most persistent opponent, Marie-Jean-Pierre Flourens (1794 -1867), was willing to admit that it was Gall who, by virtue of marshalling detailed evidence of correlation between variation in function and presumed variation in the brain, first fully established the view that brain serves as the organ of mind. In most other respects, however, Flourens was highly critical of Gall. Something of a child prodigy, Flourens enrolled at the famed Faculté de Médecine at Montpellier when he was only 15 years old and received his medical degree before he had turned. Shortly thereafter, while Gall was at the height of his career in Paris, Flourens himself moved to the capital. Based on his 1824 Recherches expérimentales sur les propriétés et les fonctions du système nerveux, he was elected to membership and eventually to the office of Perpetual Secretary of the Académie des Sciences, rising to become one of France's most influential scientific figures.
  In Recherches expérimentales, Flourens provided the first experimental demonstration of localization of function in the brain. While previous researchers had lesioned the brain through a trephined aperture that made it impossible to localize damage or to track haemorrhage with any accuracy, Flourens completely uncovered and isolated that portion of the brain to be removed. Taking care to minimize operative trauma and post-operative complications, he employed ablation to localize a motor centre in the medulla oblongata and stability and motor coordination in the cerebellum. Although his treatment of sensation was still rather confused in 1824, by the time the second edition of the Recherches expérimentales (1842) appeared, Flourens had articulated a clear distinction between sensation and perception (treating perception as the appreciation of the meaning of a sensation) and localized sensory function in several related sub-cortical structures.
 With respect to the cerebrum, however, the results were quite different. A successive order through which the hemispheres produced diffusing damage to all of the higher mental functions -to perception, intellect, and will -with the damage varying only with the extent and not the location of the lesion. If adequate tissue remained, function might be restored, but total ablation led to a permanent loss of function. From these results, Flourens concluded that while sensory-motor functions are differentiated and localized sub-cortically, higher mental functions such as perception, volition, and intellect are spread throughout the cerebrum, operating together as a single factor with the entire cerebrum functioning in a unitary fashion as their ‘exclusive seat.’
 Unfortunately, however, as Gall (1822-1825) himself observed, Flourens's procedure ‘mutilates all the organs at once, weakens them all, extirpates them all while.’ Excision by some successively given order, might arise of a method that is well in accord with the discovery of cortical localisation. Joined to a strongly held philosophical belief in a unitary soul and an indivisible mind and an uncritical willingness to generalize results from lower organisms to humans, Flourens results led him to attack Gall's efforts at localization and to formulate a theory of cerebral homogeneity that, in effect, anticipated Lashley's (1929) much later concept of mass-action and cortical equipotentiality. Having extended the sensory-motor distinction up the neuraxis from the spinal roots of Bell and Magendie, Flourens stopped short of the cerebral hemispheres. From his perspective, the cerebrum was the organ of a unitary mind, and, by implication, it could not therefore be functionally differentiated.
 Before the cortex could be construed in sensory-motor terms, the intellectual ground had to be prepared and the technical means developed. The intellectual requirements for this achievement involved the abandonment of a fixed faculty approach to mind in favour of a balanced sensory-motor, evolutionary associationism and an appreciation of the functional implications of brain disease. The technical requirement was the development of a technique for electrical exploration of the surface of the cortex. The intellectual advances came through the respective psychologies of Alexander Bain and Herbert Spencer and the neuropathological discoveries of Pierre Paul Broca. The technical advance, involving development and use of electrical stimulation, was first employed by Gustav Fritsch and Eduard Hitzig.
 Alexander Bain (1818-1903) was born, educated, and died in Aberdeen, Scotland. After receiving the MA degree from Marischal College in 1840, he joined the faculty in mental and moral philosophy. In 1860 he was elected to the chair of logic at the newly created University of Aberdeen where he remained until his retirement. During these years, Bain wrote a rare read but interesting critiques of phrenology, On the Study of Character, Including an Estimate of Phrenology (1861), and a valuable survey of mind/body views, Mind and Body. The Theories of Their Relation (1873). It is, however, to his general psychology that we must look for his most important contribution to the intellectual climate from which the first specific demonstrations of the cortical localization of sensory-motor function arose. This contribution consisted of the sensory-motor associationism that he worked out in ‘The Senses and the Intellect’ and ‘The Emotions and Will’ was first published in 1855 and 1859 respectively and revised in four editions through 1894/1899.
 Bain's work marked a turning point in the history of associationist psychology. Before Bain, the associationists' empiricist commitment to experience as the primary or only source of knowledge led to the neglect of movement and action in favour of the analysis of sensation. Even when motion was explicitly included in associationist accounts, as for example for Thomas Brown, it was the sensory side of movement, the ‘muscle sense,’ rather than adaptive action that claimed attention. Bain, drawing heavily on Müller, brought the new physiology of movement into conjunction with an associationist account of mind. As Young (1970) has summarized Bain's view: ‘Action is more intimate and has to some inseparable property, for which is based upon our constituent components that bring the composite formulations that seal us to the inseparability with the universe, and likewise our conscious selves are to realize that the universe are conscious of us, because this constitutes to any sensation and in fact, enters as the composite part into every part that we can by enacting of any senses give by them, that, only by virtue of our characterological infractions, that put forward of exaggerations, and that only we can be by the uniting the totalities to elaborate upon their flowing components. Some the spontaneity of movements, that feature of nervous activity before any evidence of independent of sensation. The acquired linkages of spontaneous movements with the pleasure and pains consequent upon them, educate the organism so that its formerly random movements  . . . (are) adapted to ends or purposes. Bain defines volition as this compound of spontaneous movements and feelings. The coordination of motor impulses into definite purposive movements results from the association of ideas with them.’
 Within association psychology, these were revolutionary ideas. With the evolutionary conceptions of Spencer, they paved the way for the later functionalist psychology of adaptive behaviour.  As we will see, they provided the intellectual context for a sensory-motor account of the physiological basis of higher mental functions. Ironically, however, this was a step that Bain himself was completely unable to take. Impressed, as those before he had been, with the lack of irritability exhibited by the cortex when pricked or cut, Bain drew the traditionally sharp distinction ‘between the hemispheres and the whole of the ganglia and centres lying beneath them.’ Whatever the function of the cerebrum, it was clear to Bain that it could not be sensory-motor.
 In 1855, the same year in which Bain published The Senses and the Intellect, another even more revolutionary work appeared in England. The Principles of Psychology  by Herbert Spencer (1820-1903) offered students of the brain an evolutionary associationism and a related concept of cerebral localization that gave impetus and direction to the work of John Hughlings Jackson and through Jackson to that of David Ferrier.
 Spencer was born in Derby, England and was largely self-taught. At the age of 17, he took up railway engineering but left that occupation in 1848 to work first as an editor and then as a free-lance writer and reviewer. In an Autobiography (1904), Spencer tells us that, at age 11 or 12, he attended lectures by Spurzheim that for many years made him a believer in phrenology. Indeed, as late as 1846, before his growing scepticism regarding phrenology led him to abandon the project, Spencer had designed a cephalograph for achieving more reliable cranial measurement.
 In 1850, because of a burgeoning friendship with George Henry Lewes, Spencer began to read Lewes's ‘A Biographical History of Philosophy,’ (1845/1846). Within a short time, he found himself so absorbed in the topic that he decided to make a contribution of his own to philosophy as an introduction to psychology. In 1855, Spencer's Principles of Psychology appeared. It is a complex and difficult book, hardly an introduction to the topic. Like Bain's work shows in ‘The Senses and the Intellect,’ it too marked a turning point in the history of psychology. While Bain had married movement to the sensations of the associationism and arrived at the first fully balanced sensory-motor associational view, Spencer went further to explicate upon the reasoning through which psychology is inferred too for being connected to evolutionary biology.
 In particular, Spencer stressed three basic evolutionary principles that transformed his view of mind and brain into one to which the cortical localization of function was a simple logical corollary. In so doing, he lay the groundwork for Hughlings Jackson's evolutionary conception of the nervous system and extension of the sensory-motor organizational hypothesis to the cerebrum. Spencer's key principles were adaptation, continuity, and development.
 Like Gall, Spencer viewed psychology as a biological science of adaptation. ‘All those activities, bodily and mental, which constitute our ordinary idea of life  . . .  (and) those processes of growth by which the organism is brought into general fitness for those activities’  consist simply of ‘the continuous adjustment of internal relations to external relations.’ Neither the associations among internal ideas, for example, nor the relations among external events, but the increasing adjustment of inner to outer relations must lie at the heart of psychology. Indeed, for Spencer, mental phenomena are adaptations, ‘incidents of the correspondence between the organism and its environment.’
 Like adaptation, continuity and development were also focal ideas for Spencer. Development consists of a change from homogeneity to heterogeneity, from relative unity and indivisibility to differentiation and complexity. According to the principle of continuity, life and its circumstances exist at all levels of complexity and correspondence. How much life varies continuously with the correspondence? ; no radical demarcations separate one level from the next. Thus, mental and physical life are simply species of life in general, and that which we call mind evolves continuously from physical life -reflexes from irritations, instincts from compounded reflexes, and conscious life and higher mental processes from instincts -co-existing at varied levels of complexity.
 The implications of these evolutionary conceptions for the hypothesis of cortical localization of function are clear. The brain is the most highly developed physical system we know and the cortex is the most developed level of the brain. As such, it must be heterogeneous, differentiated, and complex. Furthermore, if the cortex is a continuous development from sub-cortical structures, the sensory-motor principles that govern sub-cortical localization must hold in the cortex as well. Finally, if higher mental processes are the product of a continuous process of development from the simplest irritation through reflexes and instincts, there is no justification for drawing a sharp distinction between mind and body. The mind/body dichotomy that for two centuries had supported the notion that the cerebrum, functioning as the seat of higher mental processes, must function according to principles radically different from those descriptive of sub-cerebral nervous function, had to be abandoned.
 While these ideas were to be worked out more fully by Hughlings Jackson, it is quite clear that even in 1855 Spencer was well aware of the implications of his concepts of continuity and development for cerebral localization. In the Principles, he wrote that ‘no physiologist who calmly considers the question concerning the general truths of his science, can long resist the conviction that different parts of the cerebrum subserve different kinds of mental action. Localisation of a dynamic function is the law of which all coordinate system that are affiliated organizations, . . . that every packet of nerve-fibres and every ganglion, have a different and differentiated duty, can it be, then, that in the greatest of hemispheric ganglions is exclusively specializing by its particular duty that suits but for no other purpose than not to hold.
 With the ground prepared by the sensory-motor associationism of Bain and the evolutionary psychophysiology of Spencer, all needed to overcome the last obstacle to extension of the sensory-motor view to the cortex was the impetus provided by striking research findings and new experimental techniques. In the period between 1861 and 1876, Broca, and Fritsch and Hitzig, provided the first critical findings and techniques, as Jackson was persuasively unduly of influencing Spencer and Bain, thus providing the extension of the sensory-motor paradigm to the cortex. As Ferrier, unduly influenced by Bain and Jackson, provided the experimental capstone to the classical doctrine of cortical localization.
  Paul Broca (1824-1880)  was born in the township of Sainte-Foy-La-Grande in the Dordogne region of France and studied medicine at the Hôtel Dieu in Paris. A lifelong interest in physical anthropology led to his becoming in the original membership of the Société d'Anthropologie and the founder of the Revue d’Anthropologie and the Department of Anthropology at the University of Paris. On the 4th of April 1861, at a meeting of the Société d'Anthropologie, Broca sat in the audience as Ernest Aubertin presented a paper citing several striking case studies to argue the craniological case for cerebral localization of articulate language.
 Aubertin was the student and son-in-law of Jean Baptiste Bouillaud, a powerful and distinguished figure in Parisian scientific circles, himself a student of Gall and founding member of the Société Phrénologique. As early as 1825, Bouillaud had published a paper that employed clinical evidence to support Gall's view that the faculty of articulate language resides in the anterior lobes of the brain. For almost 40 years, in the face of considerable opposition, Bouillaud had succeeded in keeping the cerebral localization hypothesis alive. Thus, Aubertin was merely carrying on in his father-in-law's tradition when he promised to give up his belief in cerebral localization if even a single case of speech loss could be produced without a frontal lesion.
 Intrigued, Broca decided to take up Aubertin's challenge. Within a week, an M. Leborgne (‘Tan’), a speechless, hemiplegic patient died of gangrene on Broca's surgical ward. In the ‘Remarques sur le siége de la Faculté du langage articulé, suivies d'une observation d'aphemie (perte de la parole),’ published in 1861 in the Bulletins de la société anatomique de Paris, Broca presented a detailed account of his postmortem examination of Tan's brain. What he had found, of course, was a superficial lesion in the left frontal lobe, a finding confirmed a few weeks later by another case in which postmortem examination revealed a similar lesion.
 While neither is represented by the contentual representation of a faculty articulated by language nor even the notion of its localization in the anterior portion of the brain were especially novel in 1861, what Broca provided was a research finding that galvanized scientific opinion on the localization hypothesis. The detail of Broca's account, the fact that he had gone specifically in search of evidence for the patients' speech loss rather than employing case’s post hoc as support for localization, his use of the pathological rather than the craniological method, his focus on the convolutional topography of the cerebral hemispheres, and, perhaps what is most important, the fact that the time was ripe for such a demonstration, all contributed to the instantaneous sensation created by Broca's findings. Now all needed was a technique for the experimental exploration of the surface of the hemispheres, and this technique was contributed jointly by Gustav Theodor Fritsch (1838-1927) and Eduard Hitzig (1838-1907).
 In 1870, Archie’s für Anatomie, Physiologie, und wissenschaftliche Medicin, Fritsch and Hitzig published a classic paper that not only provided the first experimental evidence of cortical localization of function but, at a single stroke, swept away the age-old objection to localization based on the idea that the hemispheres fail to exhibit irritability. Employing galvanic stimulation of the cerebrum in the dog, Fritsch and Hitzig provided conclusive evidence that circumscribed areas of the cortex are involved in movements of the contralateral limbs and that ablation of these same areas leads to weakness in these limbs. Their findings established electrophysiology as a preferred method for the experimental exploration of cortical localization of function and demonstrated the participation of the hemispheres in motor function.
 At approximately the same time in England, John Hughlings Jackson (1835-1911) was converging from a different direction on a sensory-motor view of hemispheric function. Hughlings Jackson  was born in Providence Green, Green Hammerton, Yorkshire, England. He began the study of medicine as an apprentice in York and completed his education at the Medical School of St. Bartholomew's Hospital in London and the University of St. Andrews. Among several hospital appointments, perhaps his most important was as physician to the National Hospital for the Paralysed and Epileptic, Queen Square. His contributions to neurology and psychology are scattered throughout papers appearing in a variety of journals between 1861 and 1909. Many more important papers have been gathered in the two volumes Selected Writings of John Hughlings Jackson, edited by James Taylor (1931/1932).
 While Jackson's specific contributions to our understanding of the etiology, course, and treatment of neurological disorders ranging from aphasia and chorea to epilepsy and vertigo were very important, it is his evolutionary conception of the localization of sensory-motor function in the cerebrum that was most influential for psychology. This conception was, of course, developed under the inspiration of Spencer. As Young (1970) describes it, ‘Spencer's principles of continuity and evolution gave Jackson a single, consistent set of variables for specifying the physiological and psychological elements of which experience, thought, and behaviour are composed: sensations (or impressions) and motions. All complex mental phenomena are made up of these simple elements  --from the simplest reflex to the most sublime thoughts and emotions. All functions and faculties can be explained in these terms.’
 Jackson's paper, ‘On the anatomical and physiological localisation of movements in the brain,’ serialized in the Lancet in 1873, represents a series of papers during this period that reflect the sensory-motor conception. In an interesting and revealing preface to a 1875 pamphlet, Clinical and Physiological Researches on the Nervous System [17], which reprints the 1873 paper, Jackson describes the background for the hypothesis as it developed in his own work, almost as though he is endeavouring to establish his priority. Fond as always of quoting himself, Jackson reprints a footnote from a 1870 paper, ‘The study of convulsions,’ that summarizes his views: ‘It is asserted by some that the cerebrum is the organ of mind, and that it is not a motor organ. Some think the cerebrum is to be likened to an instrumentalist, and the motor centres to the instrument.  One part is for ideas, and the other for movements. It may, then, be asked, How can it discharge the part that assumes to other mental states, in that, of a mental organ might produce motor symptoms only? But of what substantiated results can each in substances embark upon that which is considered for the organ of mind, unless of specified processes representing movements and impressions . . . ? Are we to believe that the hemisphere is constructed of the plan that presses upon its fundamental frequency of differences, in that, its judging gauge of which an immeasurable quality of dissimilar values may yet come from that of the motor tract? . . . Surely the conclusion is irresistible that 'mental' symptoms . . . must all be due to lack, or to disorderly development, of sensor-motor processes.
 Thus, by the early 1870s, Jackson had fully articulated a general conception of the functional organization of the nervous system. In the words of Young (1970), this layed the groundwork for the last stage in the integration of the association psychology with sensory-motor physiology . . . (and) involved an explicit rejection of . . . work that had hindered a unified view: the faculty formulation of Broca, and the unwillingness of Flourens, Magendie, Müller, and others to treat the organ of mind -the highest centres -on consistently physiological terms. In Jackson's work, the theoretical analysis of cerebral localization reached the full extent of its 19th century development. In the systematic, experimental investigations of his friend and colleague, David Ferrier (1843-1928), this analysis was strikingly confirmed.
 Ferrier  was born and educated in Aberdeen, Scotland where he studied under Alexander Bain. At Bain's urging, he journeyed to Heidelberg in 1864 to study psychology. During that period, Heidelberg was home to both Helmholtz and Wundt. Indeed Wundt had only recently (1862) completed the Beiträge zur Theorie der Sinneswahrnehmung that contains the first programmatic statement of his physiological psychology and Ferrier must certainly have encountered Wundt's views.
 On his return, Ferrier completed his medical training at the University of Edinburgh and served, for a short time, as assistant to Thomas Laycock, who had been the first to articulate the concept of ‘unconscious cerebration.’ Among other appointments, Ferrier, like Jackson, served as physician to the National Hospital, Queen Square. Influenced as Jackson had been by Bain and Spencer, Ferrier set out to test Jackson's notion that sensory-motor functions must be represented through some orderly coordinative vectors systemized, since they are an organization that proudly fashions in the cortex  to extend by Fritsch and Hitzig's experimental localization of motor cortices in the cervixes of the dog. Employing very carefully controlled ablations and faradic stimulation of the brain, an advance over the galvanic techniques available to Fritsch and Hitzig, Ferrier succeeded in mapping sensory and motor areas across a wide range of species. His first paper, ‘Experimental researches in cerebral physiology and pathology,’ appeared in 1873 in the West Riding Lunatic Asylum Medical Reports. Although, it was the impact of the cumulated cross-species research that brought into all of their priorities in 1876 in The Functions of the Brain that served to confirm the installation of sensory-motor analysis as the dominant paradigm for explanation in both physiology and psychology.
 While the debate raged between Nancy and the Salpêtrière, Pierre Janet (1859-1947) was at work at Le Havre gathering clinical observations on which to base his dissertation. Born in Paris, Janet entered the École Normale Supérieure in 1879, placing second in the extremely competitive examinations of the agrégation. Shortly thereafter he took up a professorial position in philosophy at the Lyceum in Le Havre where he remained until the acceptance of his dissertation. Upon receipt of the degree, he moved to Paris to study medicine and pursue clinical research under Chariot at the Salpêtrière.
 Janet's dissertation, L'automatisme psychologique  brought together a wealth of related clinical information on a variety of abnormal mental states related to hysteria and psychosis. Dividing such states into total (involving the whole personality) and partial (part of the personality split from awareness and following its own psychological existence) automatisms, Janet employed automatic writing and hypnosis to identify the traumatic origins and explore the nature of automatism. Syncope, catalepsy, and artificial somnambulism with post-hypnotic amnesia and memory for prior hypnotic states were analysed as total automatisms. Multiple personalities, which Janet called ‘successive existence,’ partial catalepsy, absent-mindedness, phenomena of automatic writing, post-hypnotic suggestion, the use of the divining rod, mediumistic trance, obsessions, fixed ideas, and the experience of possession were treated as partial automatisms.
 What is most important, Janet brought these phenomena together within an analytic framework that emphasized the ideomotor relationship between consciousness and action, employed a dynamic metaphor of psychic force and weakness, and stressed the concept of ‘field of consciousness’ and its narrowing because of depletion of psychic force? Within this framework, Janet analysed the peculiar fixation of the patient on the therapist in rapport about the distortion of the patient's perception, and related hysterical symptomatology to the autonomous power of ‘idées fixes’ split from the conscious personality and submerged in the subconscious. Although careful to avoid direct discussion of the therapeutic implications of his work draws from a substantiating medical dissertation, Janet laid the foundations for his own and Freud's later therapeutic approaches through his demonstration of the origins of splitting in psychic traumas in the patient's history.
 Indeed, it was but a short leap from the work of Chariot, Bernheim, and Janet to that of Josef Breuer (1842-1925) and Sigmund Freud (1856-1939). In 1893, Breuer and Freud published a short preliminary communication, ‘Ueber den psychischen Mechanismus hysterische Phänomene’ in the Neurologische Centralblatt. The origin of the Breuer and Freud paper lay in Breuer's work with the famous patient Anna O.
 Although actual details of the case of Anna O. as described by Bremer, who undoubtedly took pains to disguise his patient, and many years later by Jones (1953/1957) are at considerable variances with one another and probably with the facts of the case, it is known that the alleviation of Anna O's symptoms occurred only as the patient, under hypnosis, provided Bremer in reverse chronological order with an account of the exact circumstances under which each symptom appeared. Only when she had traced the final symptom back to the traumatic circumstances of its occurrence was she cured. Anna O's cure by this ‘cathartic’ method, which involved bringing the trauma to consciousness and allowing it to discharge through effect, words, and guided associations, has often been seen, and was thought by Freud, to be the starting point for psychoanalysis.
 In the seminal work of Janet and in the critical transitional paper of Bremer and Freud, we see the culmination of developments that had begun with Puységur's elaboration of the doctrines of Mesmer. In a little more than a hundred years, a huge corpus of evidence and relational neurological functions and psychological theories that are dynamically irrevokable, least of mention, there is to believe that the related mental states, or their events -mesmeric trance states, rapport, the therapist's will to cure, the concentration of attention, mental suggestion, psychic trauma, the dissociation of consciousness, and catharsis -could affect radical alterations in the state of the body. No psychologist writing in the 1890s could afford to ignore this rich material and its implications for conceptualization of the nature of the mind/body relationship. William James, as we will see, was no exception. According to the received view (Boring, 1950), scientific psychology began in Germany as a physiological psychology born of a marriage between the philosophy of mind, on the one hand, and the experimental phenomenology that arose within sensory physiology on the other. Philosophical psychology, concerned with the epistemological problem of the nature of knowing mind in relationship to the world as known, contributed fundamental questions and explanatory constructs; sensory physiology and to a certain extent physics contributed experimental methods and a growing body of phenomenological facts.
 In one version of this story that can be traced back at least to Ribot (1879), the epistemology of the 17th and 18th centuries culminated in the work of Kant, who denied the possibility that psychology could become an empirical science on two grounds. First, since psychological processes vary in only one dimension, time, they could not be described mathematically. Second, since psychological processes are internal and subjective, Kant also asserted that they could not be laid open to measurement. Herbart, so the tale goes, answered the first of Kant's objections by conceiving of mental entities as varying both in time and in intensity and showing that the change in intensity over time could be mathematically represented. Fechner then answered the second objection by developing psychophysical procedures that allowed the strength of a sensation to be scaled. Wundt combined these notions, joined them to the methods of sensory physiology and experimental phenomenology and, in 1879, created the Leipzig laboratory.
 While there is undoubted truth in the received history, like all rationalizing reconstructions, it tends greatly to oversimplify what is an exceptionally complex story. Within the past 20 years, as primary resource materials have become more widely available and as larger numbers of historians have entered the arena, the received view has been amended often. Within the context of this exhibit catalogue, it will not, of course, be possible to address this complexity. The reader who is interested, however, is referred to the Journal of the History of the Behavioural Sciences and to Bringmann and Tweney (1980), Danziger (1990), Rieber (1980), and Woodward and Ash (1982) among others.
 Because so many psychologists are at least broadly familiar with the lines of Boring's story of the rise of experimental psychology, because the story has been so frequently retold in the many other textbook histories, and because it is a much more complex tale that it at first appears, this section and the two to follow will sketch only the barest outlines of the intellectual developments that led from Locke to Kant, from Bell to Müller, and from Fechner to Wundt. Psychologists who have not read Boring are strongly encouraged to do so. Despite its limitations, it is still the point of origin from which much of contemporary scholarship proceeds.  Perhaps even more important, it is the history of psychology that has become part and parcel of American psychology's view of itself.
 Immanuel Kant (1724-1804)  was born, lived, and died at Königsberg, in East Prussia. It is said that in the entire course of his life, he never travelled more than forty miles from the place of his birth. The suggestion from Ribot that 18th century philosophy culminated in the work of Kant was probably not an unreasonable one; although it might be an even fairer appraisal of Kant's influence to say that 19th and 20th century philosophy followed Kant much as the earlier philosophy had followed Descartes. Kant's indirect influence on scientific psychology was therefore enormous. His direct contributions, although admittedly more circumscribed, were also very important
 One such contribution, as we have already noted, was Kant's defining the prerequisites that would need to be met for psychology to become an empirical science. Another consisted of a bonafide psychological treatise, Anthropologie in pragmatischer Hinsicht, published in 1798. Long ignored, probably in part because of its pronounced sympathy for as soon as to be a discredited physiognomy, the Anthropologie is, nonetheless, a fascinating little book. Here Kant analyses the nature of the cognitive powers, feelings of pleasure and displeasure, affects, passions, and character in a denial of the possibility of an empirical science of conscious process. The Anthropologie went through two editions during Kant's lifetime and several later printings and helped to define the context within which not only Herbart and Fechner but phenomenologically oriented physiologists such as Purkyne, Weber, and Müller worked to establish the science of conscious phenomena that Kant was unable to envision.
 Boring (1950) has pointed out that between the years remembered through about the 1800s and well through to bout 1850, when several discoveries in physiology helped lay the foundation for the eventual rise of experimental psychology. The events’ particularity of interest are: (a) the first elaboration of a distinction between sensory and motor nerves; (b) the emergence of a sensory phenomenology of vision and of touch; and © the articulation of the doctrine of specific nerve energies, including the related view that the nervous system mediates between the mind and the world. While these discoveries were being made, two major developments in philosophical psychology were also occurring: the elaboration of secondary laws of association and the first attempt at a quantitative description of the parameters affecting the movement of ideas above and below a threshold.
 Johannes Müller (1801-1858)  was born in Coblenz and educated at the University of Bonn. He received his medical degree in 1822 and, after a year in Berlin, was habilitated as privatdozent at Bonn, where he rose eventually to the professoriate. In 1833, he left Bonn to assume the prestigious Chair of Anatomy and Physiology at the University of Berlin. His most important contributions to the history of experimental psychology were the personal influence that he exerted upon younger colleagues and students, including Hermann von Helmholtz, Ernst Brücke, Carl Ludwig, and Emil DuBois-Reymond, and the systematic form he gave to the doctrine of the specific energies of nerves in the Handbuch der Physiologie des Menschen für Vorlesungen, published between 1834 and 1840.
 Although Müller had enunciated the doctrine of specific nerve energies as early as 1826, his presentation in the Handbuch was more extensive and systematic. Fundamentally, the doctrine involved two cardinal principles. The first of these principles was that the mind is directly aware not of objects in the physical world but of states of the nervous system. The nervous system, in other words, serves as an intermediary between the world and the mind and thus imposes its own nature on mental processes. The second was that the qualities of the sensory nerves of which the mind receives knowledge in sensation are specific to the various senses, the nerve of vision being normally as insensible to sound as the nerve of an audition is to light.
 As Boring (1950) pointed out, there was nothing in this view that was completely original with Müller. Not only was much of the doctrine contained in the work of Charles Bell, the first of Müller's two most fundamental principles was implicit in Locke's idea of ‘secondary qualities’ and the second incorporated an idea concerning the senses that had long been generally accepted. What was important in Müller was his systematization of these principles in a handbook of physiology that served a generation of students as the standard reference on the subject and the legitimacy he lent the overall doctrine through the weight of his personal prestige.
 After Müller, the two problems of mind and body, the relationship of mind to brain and nervous system and the relationship of mind to a world were inextricably linked. Although Müller did not himself explore the implications of his doctrine for the possibility that the ultimate correlates of sensory qualities might lie in specialized centres of the cerebral cortex or develop some sensory psychophysics, his principle of specificity lay the groundwork for the eventual localization of cortical function and his view of the epistemological function of the nervous system helped define the context within which techniques for the quantitative measurement of the mind/world relationship emerged in Fechner's psychophysics.
 It is in the work of Gustav Theodor Fechner (1801-1887) that we find the formal beginning of experimental psychology. Before Fechner, as Boring (1950) tells us, there was only psychological physiology and philosophical psychology. It was Fechner ‘who performed with scientific rigour those first experiments which laid the foundations for the new psychology and still lie at the basis of its methodology’
 On the 24th of March 1879, however, Wundt submitted a petition to the Royal Saxon Ministry of Education in which he formally requested a regular financial allocation for the establishment and support of a collection of psychophysical apparatus. Although his request was denied, Wundt seems as early as the Winter of 1879/1880 to have nonetheless allowed two students, G. Stanley Hall and Max Friedrich, ‘to occupy themselves with research investigations.’ This research took place in a small classroom in the Konvict Building that had earlier been assigned to Wundt for use as a storage area. Humble though it may have been, this small space constituted the first laboratory in the world devoted to original psychological research.
 Experimental psychology, born with Fechner, nurtured by Helmholtz and Donders, was to be raised by Wundt. Over the years until his retirement in 1917, Wundt served as the de facto parent of the ‘new’ psychology. Students from all over the world, especially from the United States, journeyed to Leipzig to learn experimental technique and to return to their home institutions imbued with the spirit of scientific psychology.
To occupy oneself with history is not a matter of simple curiosity. It would be so if history were a simple science of the past. But: (1) History is not a simple science. (2). One does not make one’s home the singularity that can only to grasp into its self that one can be the accompaniment within the past, inasmuch as it no longer exists. History is not a simple science, but rather there exists a historical reality. Historicity, in fact, is a dimension of the real being we call 'man'.
 And this historicity does not arise exclusively or primarily because of the fact that the past advances toward a present, and pushes it on toward the future. This later is a positive interpretation of history that is completely inadequate. It presupposes, in fact, that the present is just something that passes, and that the passing means what once was no longer is. The truth on the contrary is that an existing reality, and hence one that is present, man, finds himself constituted partially through a possession of himself in such a form that when he turns in upon himself, he discovers himself being what he is because he had a past and is being formed for a future. The ‘present’ is that marvellous unity of these three moments whose successive unfolding constitutes the historical trajectory, the point at which man, a temporal being, paradoxically becomes the tangent to eternity. Since Boethius, in fact, the classical definition of eternity has involved not just ‘an inter-mirabilis vita,’ as a never-ending life, but ‘tota simul et perfecta possessio.’ Furthermore, the reality of man present is constituted among other things by that concrete point of tangency whose geometric locus is termed the situation. Upon entering into ourselves, we discover that we are in a situation that pertains to us constitutively, and in which our individual destiny is inscribed, a destiny elected by us sometimes, imposed on us others. And while the situation does not ineluctably predetermine either the content of our life or that of its problems, it clearly circumscribes the general nature of those problems, and  above all limits the possibilities for their solution. Hence, history as a science is much more a science of the present than a science of the past. In respect to philosophy, this is even truer than it could be for any other intellectual occupation, because the character of philosophical knowledge makes of it something constitutively problematic. Zetoumene episteme, the sought after science, Aristotle usually termed it. Therefore it is pot at all strange that to profane eyes, the problem has an atmosphere of discord.
 In history we encounter three distinct conceptions of philosophy, emerging ultimately from three dimensions of man: (1)  Philosophy as a knowledge about things (2)  Philosophy as a direction for the world and for life. (3)  Philosophy as a way of life and therefore as something that happens.
 In reality, these three conceptions of philosophy, corresponding to three different conceptions of the intellect, lead to three completely different forms of intellectuality. The world has continued to nourish itself on them, simultaneously and successively, at times even in the person of one thinker. The three converge in a special way in our situation, and again keenly and urgently pose the problem of philosophy (and of intellect itself). These three dimensions of the intellect have reached us, perhaps somewhat dislocated, through the channels of history.  The intellect has itself begun to pay for its own deformation. In trying to reform itself, it seems readily sure, in that the future new forms of intellectuality. All of the earlier ones, they will be defective, or rather limited. However that does not disqualify them, because man is always what he is, but thanks are by his restrictive nature, as too, are the limitations, for which permit of him of choice, for which he can be. And if, by his perceptivity that their own limitations are the intellectuals of that lived of that time, perhaps, a returning source from which they can depart, just as we see ourselves referred to identify the place of which we depart. And this is history: a situation that implies another previous one, as something real making possible our own situation. Thus, to occupy oneself with history is not a simple matter of curiosity; it is the very movement to which the intellect sees itself subjected when it embarks on the enormous task of setting itself in motion starting from its ultimate source. Therefore the history of philosophy is not extrinsic to philosophy itself, as the history of mechanics could be to mechanics. Philosophy is not its history, but the history of philosophy is philosophy, because the turning in of the intellect upon itself, in the concrete and radical situation in which it finds itself placed, is the origin take-off point for philosophy. The problem of philosophy is nothing but the problem of the intellect. With this affirmation, which ultimately goes back to old Parmenides, philosophy began to exist on the earth. And Plato used to tell us, moreover, that philosophy is a silent dialogue of the soul with itself concerning all things in being.
 Still, the practising scientist will only with difficulty succeed in freeing himself from the notion that philosophy becomes lost in an abyss of discord, if not throughout its domain, at least insofar as it involves knowledge about things.
 It is undeniable that throughout its history, philosophy has understood its own definition as a knowledge about things in quite diverse ways. But the first responsibility of the philosopher must be that of guarding himself against two antagonistic tendencies that spontaneously arise in a beginning spirit: That of losing oneself in skepticism and that of deciding to fit tightly polemically, as having a difference of opinion across one system instead of another, even if it is that we are as oriented differently of our position in life, only that if we could be formulated. We will renounce these attitudes. And if we now review the rich collection of definitions, we cannot fail to be overwhelmed by the impression that a very serious matter is at the heart of this diversity. If the conceptions of philosophy as a theoretical form of knowledge are truly so diverse, it is clear that this diversity means that not only the content of its solutions, but the very idea of philosophy continues to be problematic. The diversity of definitions manifest the problem of philosophy itself as a true form of knowledge about things. But to think that the existence of such a problem could disqualify philosophy as its theoretical knowledge is to condemn the paradigms by which of science has given by oneself the perpetual persistence, which, perhaps, leaves its shoes outside its vestibule. The problems of philosophy are not, at bottom, other than the problem of philosophy.
 But perhaps the question will resurface with new urgency when we try to pin down the nature of this theoretical knowledge. Nor is the problem even new. For quite some time, several centuries in fact, this question has been formulated another way: Does philosophy have scientific character? However, this manner of presenting the problem is not quite the same. According to it, ‘knowledge about things’ acquires its complete and exemplary expression in what is termed ‘a scientific form of knowledge.’ And this supposition has been decisive while philosophy the modernity of times due, stood very still.
 In diverse ways, in fact, it has been repeatedly observed that philosophy is quite far from being a science, that in most of its hypotheses it does not go beyond an attempt to be scientific. And this may lead either to skepticism about philosophy, or to maximum optimism about it, as occurred in Hegel when in the opening pages of the Phenomenology of the Spirit he roundly affirms that he proposes to ‘help to bring philosophy nearer to the form of science, . . . show that the time process does raise philosophy to the level of scientific system . . .’ And he also affirms that it is necessary for philosophy to abandon, its character of love and of wisdom to be converted into some activated wisdom. (For Hegel, ‘science’ does not mean science in the usual sense.)
 With a different objective, but with less energy, Kant begins the preface to the second edition of the Critique of Pure Reason by saying:
Whether the treatment of knowledge lies within the province of reasons served or does not follow the secure path of a science, is easily to be determined from the outcome. For if after elaborate preparations, frequently renewed, it is brought to a stop immediately it nears its goal; if often it is compelled to retrace its steps and strike into some new line of approach; or again, if the various participants are unable to agree in any common plan of procedure, then we may rest assured that it is very far from entering upon the secure path of a science, and is indeed a mere random groping.
 And in contrast to what occurs in logic, mathematics, physics, etc., with respect to metaphysics we see that . . .  though it is older than all other sciences, and would survive even if all the rest were swallowed up in the abyss of an all-destroying barbarism, it has not yet had the good fortune to enter upon the secure path of a science.
 A quarter of a century ago Husserl published a vibrant study in the periodical Logos, entitled ‘Philosophy as a Strict and Rigorous Science.’ In it, after having shown that it would be nonsense, for example, to discuss a problem of physics or mathematics so the participants injected into the discussion their own points of view, their opinions, preferences, or Weltanschauung, Husserl boldly proposes the necessity of making philosophy likewise into a science of apodeitic and absolute evidence. But in him last analysis, he merely refers to the work of Descartes. Descartes, very cautiously but at bottom saying the same thing, begins his Principles of Philosophy as follows: As we were at once children, and as we formed various judgements regarding the objects presented to us, when yet we had not the entire use of our reason, numerous prejudices stand in the way of our arriving at the knowledge of truth.  Of these it seems impossible for us to rid ourselves, unless we undertake, once in our lifetime, to doubt of all these things in which we may discover even the smallest suspicion of uncertainty.
 From this exposition of the question we may draw several important conclusions: 1. Descartes, Kant, and Husserl compare philosophy to the other sciences from the point of view of the type of knowledge that they yield: Does philosophy or does it not possess a type of apodeitic evidence comparable to that of mathematics or theoretical physics? 2. This comparison later reverts to the method that leads to such evidence: Does philosophy or does it not possess a method that leads securely, through internal necessity and not merely by chance, to types of evidence analogous to those obtain by the other sciences? 3. Finally it leads to a criterion: insofar as philosophy does not possess this type of knowledge and this secure method of the other sciences, its defect in that regard becomes an objection to its scientific character.
 Now, faced with this statement of the question we must energetically affirm: 1. That the difference that Husserl, Kant and Descartes point out between science and philosophy, though very important, is not in the end sufficiently radical. 2. That the difference between science and philosophy is not an objection to the character of philosophy as a strict form of  knowledge about things.
 And this is so because, in the last analysis, their objection to philosophy derives from a certain conception of science that, without prior discussion, is assumed applicable to all strict and rigorous knowledge
 The radical difference separating philosophy and the sciences does not arise from the scientific or philosophical state of knowledge. It seems, listening to Kant, that the only thing that matters is that, relative to its object, philosophy (in contrast to science) has not yet managed to give us a single reliable step leading to that state of knowledge. And we affirm that said difference is not sufficiently radical, because frankly it presupposes that the object of philosophy is there, in the world, and that all we need do is find the secure road leading to it.
 The situation would be much more serious if what were problematic turned out to be the object of philosophy: Does the object of philosophy exist? This question is what radically separates philosophy from the other sciences. Whereas these latter starts from the possession of their object, and then simply study it, philosophy must begin by actively justifying the existence of its object, the possession of which is in fact the end, not the presupposition of its study. And philosophy can only be an on-going concern by constantly recovering the existence of its object. When Aristotle termed it Zetoumene episteme, he understood that what men sought was not only the method, but the very object of philosophy as well.
 What does it mean to say that the existence of the object of philosophy is problematic?
 If this meant simply that we were ignorant of what that object is, the problem, though serious, would ultimately be quite simple. It would be a question of saying either that humanity has not yet discovered that object, or that it is so complicated that its apprehension is still obscure. To be sure, the former is what happened for many centuries with each science and therefore their respective object: were not simultaneously discovered during history? ; some sciences were born later than others. On the other hand, if it were true that the object of philosophy were excessively complicated, the question would be that of trying to show it only to those minds who had acquired sufficient maturity. This would be analogous to the difficulty encountered by someone who tried to explain the object of differential geometry to a student of mathematics in elementary school. In either of these cases, owing to historical vicissitudes or didactic difficulties, we would be dealing with a deictic problem, with an individual or collective effort to point out (deixis) what that object is which goes about here lost among the other objects of the world.
 Everything leads us to suspect that this is not so.
 The problematicism surrounding the object of philosophy stems not only from a de facto failure to come upon it, but moreover from the nature of that object, which, in contrast to all others, is constitutively latent. Here we understand by ‘object’ the real or ideal thing with which science or any other human activity deals. Here, it is clear that: (1). This latent object is in no way comparable to any other object. Therefore, in as much as we what wish of saying, the object of philosophy, may, perhaps, find as a propounding asset, that we will move as if on the axial plane of thought, afar and above, that once removed we begin to participate of the other sciences. If each science deals with an object, either real, fictitious, or ideal, the object of philosophy is neither real, fictitious, nor ideal; it is something else, so much so, that it is not a thing at all. (2) We thus understand that this peculiar object cannot be found separated from any other object, be it real, fictitious, or ideal. Nonetheless, may it be, that it is included in all of them, without being identified with any particular one. This is what we mean when we affirm that it is constitutively latent, latent beneath every object. Since man finds himself constitutively directed toward real, fictitious, or ideal objects, with which he must create his life and elaborate his sciences, it follows that this constitutively latent object is because of its own nature essentially fleeting. 3. What this object flees from is none other than the simple glance of the mind. In contrast, then, to what Descartes maintained, the object of philosophy can never be formally discovered through a simplex mentis inspectio. Rather, after the objects beneath which it lies have been understood, a new mental act reworking the previous ones is necessary to position the object in a new dimension to make this other new dimension not transparent, but visible. The act by which the object of philosophy is made patent is not an apprehension, nor an intuition, but a reflection, a reflection that does not, as such, discover a new object among the others, but a new dimension of each object, whatever it may be. It is not an act that enriches our  understanding of what things are. One must not anticipate that philosophy will tell us, for example, anything about physical forces, organisms, or triangles that is inaccessible to mathematics, physics, or biology. It enriches us simply by carrying us to another type of consideration.
 To avoid misunderstandings, we should observe that the word 'reflection' is employed here in its most ingenuous and common meaning: an act or series of acts that, in one form or another return to an object of a previous act through this latter act. 'Reflection' here does not mean simply an act of meditation, nor an act of introspection, as when one speaks of reflective consciousness, as opposed to direct consciousness. The reflection here described consists of a series of acts through which the entire world of our life is placed in a new perspective, including the objects therein and all the scientific knowledge we may have acquired about them.
 Secondly, note that though reflection and what it discovers to us cannot be reduced to a natural attitude and what it discovers to us.  This does not mean that in one fashion or another, in one degree or another, reflection is not just as primitive and inborn as any natural attitude.
 It follows then that the radical difference between science and philosophy does not fall upon philosophy as an objection. It does not mean that philosophy is not a rigorous form of knowledge, but only that it is a different type of knowledge. Whereas science is a knowledge that studies an object that is there, philosophy, since it deals with an object that because of its own nature hides, which is evanescent, will accordingly be knowledge that must pursue its object and detain it before a human gaze, which must conquer it. Philosophy is nothing but the active constitution of its own object; it is the actual carrying out of this act of reflection. Hegel's fatal error was just the opposite of Kant's. Whereas Kant, in short, divorced philosophy from any object of its own, thus making it refer to our mode of knowing. Hegel reifies about the object of philosophy, speaking as if only all of which is to every other object, there emerges of some dialectical awareness for which each one is sustained dialectically.
 For the present it is unnecessary to further clarify the nature of the object of philosophy or its formal method. Here the only thing I wish to emphasize is that irrationalism not withstanding, the object of philosophy is strictly an object of knowledge, but this  object is radically different from the rest. Whereas any science or any human activity considers things that are and such as they are (hos estin), philosophy considers them inasmuch as they are (hei estin, Metaphysics 1064). In other words, the object of philosophy is transcendental, and as such accessible only to a reflection. The ‘scandal of science’ not only isn't an objection to philosophy that must be resolved, but a positive dimension that it is necessary to conserve. Therefore Hegel said that philosophy was the world in reverse. The explanation of this scandal is the problem, content, and destiny of philosophy. Hence (although not quite what Kant said) ‘one does not learn philosophy, one learns to philosophize.’ And it is absolute certain that one only learns philosophy by starting to philosophize.
 Every science, whether history or physics or theology (and likewise every natural attitude of life) refers too more than or less determinate of objects, with which man has already come into contact. The scientist may, then, direct himself to it, and set himself one or more problems about it the attempted solutions of which constitute the reality of science. If the presumed science does not yet enjoy a clear conception of what it pursues, then it is not yet a science. Any wavering on this point is an unequivocal sign of imperfection. That does not mean the science is immutable, but what changes in it is the concrete content of the solutions given to the one or more problems it has set out to solve. The problem itself, may be that of an unaltered remission that goes beyond the remains as such. The physical view of the universe has profoundly changed from Galileo to Einstein and quantum mechanics, however, in all these changes that have occurred within the scope of a general endeavour known and defined all along, viz., measurement of the universe. Sometimes perhaps the very formulation of the problem may change. But this occurs extremely rarely and across long spans of time. When it does happen it is owing to a new formulation of the problem that is as clear and determinate as the previous one, so that one may ask, indeed, whether ultimately the science has not ceased to be what it used to be, and become something else, a different science. Thus, in the Middle Ages physics studied the principles of the physical theories that were achievable. After Galileo it was measurement of the material universe. In both cases’ physics was a science when it had begun to tell itself what it sought to do.
 Very different is the course of philosophy. In fact, philosophy begins by not knowing whether it has a proper object; at least, it does not start formally from the possession of an object. Philosophy presents itself, above all, as an effort, as a ‘pretension.’ And this, not because of any simple ignorance de facto or a simple lack of knowledge, but because of the constitutively latent nature of that object. Hence it follows that the strict separation between a problem that clearly differentiates in advance of its later solution, which is basic to all science and to all natural attitudes of life, loses its primary meaning about philosophy. Hence philosophy must be, first, a perennial revindication of its object (let us call it that), an energetic illumination of it and a constant and constitutive ‘making room.’ From Parmenides' entity (on), Plato's Ideas, and Aristotle's analogical being as such, up to Kant's transcendental conditions of experience and the absolute of Fichte, Schelling, and Hegel, passing through all the theological strata of medieval thought and the first centuries of the modern era, philosophy has been primarily a justification of or demonstrative effort for the existence (‘sit venia verbo’) of its object. Whereas science deals with an object that it already clearly possesses, philosophy is the effort directed toward a progressive intellectual constitution of its own object, the violence of yanking it from its constitutive latency and clearly revealing it. Nonetheless, philosophy might exist for the revindicating of itself, and in one of its formal dimensions consists in ‘opening paths.’ Consequently, philosophy cannot have what is the greater ascendancy than fixed by the intellectual narrowness which de facto oppresses the philosopher.
 In virtue of this, it is only clear to the philosopher after he finds himself philosophizing what a mighty labour he carried out to reach the point where he could begin to philosophize. And this is true whether one deals with obtaining rigorous evidence or rising to transcendental intuitions. In this labour of opening a path one sketches and outlines the figure of the problem. It is possible for the philosopher to have begun with a certain subjective intellectual purpose. But this does not mean that such a beginning is formally the origin of his philosophy. And if we agree that the nature of the problem is the origin of principles, we must say that, in philosophy, the origin is the end, moreover in its first original and radical ‘step’ all of philosophy is already there. Throughout this process philosophy properly speaking does not evolve, is not enriched with new characteristics; rather, the characteristics become more explicit, they continually appear as aspects of a self-constitution. Whereas an immature science is imperfect, philosophy is the very process of its own maturity. The rest is dead academic and scholarly philosophy. Hence, in contrast to what happens in science, philosophy must mature in each philosopher. And therefore that which properly constitutes its history is the history of the idea of philosophy. Hence the original relationship existing between philosophy and its history must be clarified.
 It may occasionally happen that the philosopher begins with an already existing concept of philosophy. But, what meaning or function does such a concept have within philosophy? It is, obviously, a concept that he, the philosopher has created and therefore is his possession or property. But, once things are underway, because philosophy consists of the ‘opening a path,’ it follows that therein the idea of philosophy is constituted. The definition of physics is not the work of physical science, whereas the work of philosophy is the conquest of its idea of itself.  On this point, that initial movement has no bearing whatsoever; philosophy has achieved its own consistency, and with it an adequate concept, the concept which philosophy has created for itself. Nor is it any longer the philosopher who bears the concept of philosophy, as happened at the beginning; rather, philosophy and its concept are what bear the philosopher. In that apprehension or conception that the concept is, it is no longer the mind that apprehends or conceives philosophy, but philosophy is that what apprehends and conceives in the mind. The concept is not the property of the philosopher, but rather the philosopher is the property of the concept, because these latter springs from what philosophy is in it. Philosophy is not the work of the philosopher; the philosopher is the work of philosophy.
 From where, before and only before a mature philosophy do we see that it is not only possible but necessary to ask how far and in what way does that philosophy answer its own concept. A typical case, to speak only of recent history, is shown to us by German Idealism, from Kant to Hegel. It makes perfect sense to scrutinize this entire current of transcendental idealism, and determine with each philosopher an original philosophy, absolutely compatible with the common root of all of their thought, and even with Kant's singular merit of being the first to discover the root and bear the first fruits.
 Rene Descartes was a famous French mathematician, scientist and philosopher. He was arguably the first major philosopher in the modern era to try to defeat skepticism. His views about knowledge and certainty, and his views about the relationship between mind and body have been very influential over the last three centuries.
 One source of this interest in method was ancient mathematics. The thirteen books of Euclid's Elements were some models of knowledge and deductive method. But how had all this been achieved? Archimedes had made many remarkable discoveries. How had he come to make these discoveries? The method in which the results were presented (sometimes called the method of synthesis) was clearly not the method by which these results were discovered. So, the search was on for the method used by the ancient mathematicians to make their discoveries (the method of analysis). Descartes is clearly convinced that the discovery of the proper method is the key to scientific advance. For more extended purposes and detailed discussion of these methods.
 In November 1628 Descartes was in Paris, where he made himself famous in a confrontation with Chandoux. Chandoux claimed that science could only be based on probabilities. This view reflected the dominance in French intellectual circles of Renaissance skepticism. This skptical view was rooted in the religious crisis in Europe resulting from the Protestant Reformation and had been deepened by the publication of the works of Sextus Empiricus and reflections on disagreements between classical authors. It was strengthened again by considerations about the differences in culture between New World cultures and that of Europe, and by the debates over the new Copernican system. All of this had been eloquently formulated by Montaigne in his Apology for Raymond Sebond and developed by his followers. Descartes attacked this view, claiming only that certainty could serve as a basis for knowledge, and that he himself had a method for attaining such certainty. In the same year Descartes moved to Holland where he remained with only brief interruptions until 1649.
 In Holland Descartes produced a scientific work called Le Monde or The World that he was about to publish in 1634. At the point, however, he learned that Galileo had been condemned by the Church for teaching Copernicanism. Descartes’s book was Copernican to the core, and he therefore had it suppressed. In 1638 Descartes published a book containing three essays on mathematical and scientific subjects and the Discourse on Method. These works were written in French (rather than Latin) and were aimed at the educated world rather than simply academics. In 1641 Descartes followed this with the Meditationes de Prima Philosophia (Meditations on First Philosophy). This short work is more metaphysical than scientific, and aims to establish the certain foundations for the sciences that Descartes had announced in his confrontation with Chandoux in 1628. (For a more detailed account of this work see Structure of the Meditations. The work was published with Objections and Replies from a six and then seven philosophers and theologians, including Thomas Hobbes, Pierre Gassendi and Antoine Arnauld.
 After the Meditations, Descartes produced The Principles of Philosophy in 1644, the most comprehensive statement of his mature philosophy and of the Cartesian system in general. Part (1) explains Descartes metaphysical views. Part (2) gives a detailed exposition of the principles of Cartesian physics. Part (3) applies those principles of physics to explain the universe, and Part (4) deals with a variety of terrestrial phenomena. Two more parts were planned, to deal with plants and animals and man, but were not completed. In 1648 Descartes published ‘Notes against a Program’ -a response to a pamphlet published anonymously by Henricus Regius, Professor of Medecine at the University of Utrecht. Regius had been an early and enthusiastic supporter of Descartes. Yet, once Regius published his Foundations of Physics Descartes complained that Regius had shamelessly used unpublished papers of Descartes to which he had access and had distorted Descartes' ideas. The ‘Notes’ both illustrate the kind of academic controversy in which Descartes was involved during this decade, but also provides some insight into his views about mind and his doctrine of innate ideas.
 Descartes last work Les Passions de l'áme was written because of the correspondence that Descartes carried on with Princess Elisabeth of Bohemia. The work was written in French, and published in Amsterdam and Paris in 1649. This work (like the Principles) is composed of many short articles. Princess Elisabeth had raised the question of how the soul could interact with the body in 1643. In response to Elisabeth's questions, Descartes wrote short works that developed into the ‘Passions of the Soul.’ The work is a combination of psychology, physiology and ethics, and contains Descartes' theory of two way causal interactions via the pineal gland.
 Two months before the publication of the Passions Descartes set sail for Stockholm, Sweden, at the invitation of Queen Christina of Sweden. Descartes' death in Stockholm of pneumonia, has regularly been attributed to the rigours of the Swedish climate and the fact that Descartes (no early riser) was sometimes required to give the Queen lessons as early as five in the morning. However unpleasant these conditions may have been, it seems plain that Descartes acquired his fatal malady because of nursing his friend the French ambassador (who had pneumonia) back to health. 
 Most academics are familiar with a comforting fable, subject to minor variations, about René Descartes and modern philosophy. Around 1640, Descartes philosophically crystallized a key transformation latent in Renaissance views of humanity. He moved the foundation of knowledge from humans fully embedded within and suited to nature to inside each individual. Descartes made knowledge and truth rest upon the individual subject and that subject's knowledge of his or her own capacities. This move permitted profoundly new and unconditional skepticism, than undermining universal knowledge by positing a uniformity of human subjects, this move ultimately guaranteed intersubjective knowledge. Knowledge became subjective and objective. Not content merely to make man himself the ground of knowledge, Descartes went further to make the human mind alone the source for knowledge, knowledge that modelled after pure mathematics. The new Cartesian subject ignored the manifold contributions of the body, and Descartes assumed all real knowledge could come only from a reason common to all humans. The universality of the knowing things and processes of knowing and not-knowing, are we to make of this causal event the Cartesian subject as one that is transcendental. Above all, mathematics, with its proof techniques, and formal thought, modelled on mathematics, exemplified those things that can be intersubjectively known by individual but importantly similar subjects.
 Versions of this fable appear in numerous analyses, some quite sophisticated and textually based, some crude and dismissive. These versions provide grounds for praising or dismissing Descartes and the philosophical modernity he wrought. Rather than surveying or evaluating these appraisals, here I want merely to clarify and anchor historically the subject Descartes hoped his philosophy would help produce. This essay examines one set of exercises Descartes highlighted as propaedeutics to a better life and better knowledge: Becoming famous, for which it might be that if it were as little known through his geometry. Critics and supporters have too often stressed Descartes's dependence on or reduction of knowledge to a mathematical model without inquiring into the rather odd mathematics he actually set forth as this model. His geometry, neither Euclidean nor algebraic, has its own standards, its own rigour, and its own limitations.3.  These characteristics ought radically to modify our view of Descartes's envisioned subject. Although the technical details of his geometry might seem interesting and comprehensible only to historians of mathematics, the essential features grounding Descartes's program can be made readily comprehensible. Descartes did far more than theoretically (if implicitly) invoke the knowing subject in his Meditations. To pursue his philosophy was nothing less than to cultivate and order oneself. He offered his revolutionary but peculiar mathematics as a fundamental practice in this philosophy pursued as a way of life. Let us move, then, from abstraction about Descartes to the historical quest for this way of life One way in which modern philosophy, roughly that beginning with Descartes, is supposed to be different from what came before it, is its emphasis on the problems of acquiring knowledge. This emphasis on knowledge likely has its origins in a variety of circumstances.
 One of these is the Reformation crisis concerning religious knowledge and related events. Luther questioned the Catholic criterion of religious knowledge -the Rule of Faith as it is called -and thereby started a new religion with its own criterion of religious knowledge. The Rule of Faith says that religiously knowledged is determined by what Church fathers, Church Councils and the Popes say about any particular claim. Thus Church Councils have endorsed the doctrine of the trinity so anyone who claims that this doctrine is false is a heretic. Luther replaced the Rule of Faith with the claim that all Christians have the power 'of discerning what is right or wrong in matters of faith.' Luther finally made it clear that his new view amounted to this: What conscience is compelled to believe on reading scripture is true. This radical move changed Luther from just another reformer to the founder of a new religious sect. For many people it raised an enormous problem about religious knowledge. Which of the two criteria was the correct one? It was difficult for people to determine the answer to this question. For various reasons, which we will consider, this sceptical crisis about religious knowledge developed into a full blooded sceptical crisis about knowledge in general. So how does one acquire genuine knowledge?
 One way to think about the problem of acquiring knowledge about the era we are discussing is to regard reason, the senses and faith as competing ways of getting at the truth about reality. One might hold, with Plato for example, that the senses will not get one to the truth about reality; that only reason will lead us to knowledge of reality and how to lead the best life and attain genuine happiness. Or one might argue that the senses provide knowledge of the world that is more basic than anything that reason tells us. Or, one might hold that both reason and the senses are poor guides and that only faith will reveal the way things really are.
 Skepticism is the doctrine that knowledge is not possible. One can be either a universal skeptic who holds that no knowledge whatever is possible (Could this be true?) or simply a skeptic about one faculty, like the senses, or some particular branch of knowledge, such as religious knowledge or mathematical knowledge. Skepticism is intertwined in the competition among the faculties because an advocate of reason, for example, is likely to be sceptical of the ability of the other faculties to reach the truth. The Cambridge Platonists, for example, regarded the doctrine that the senses are more important than reason as the philosophy of beasts. For men share sense knowledge with the beasts, while reason sets man apart from the beasts. An advocate of faith, on the other hand, will be sceptical of the ability of reason and the senses to provide genuine knowledge. The great French essayist Michel de Montaigne is an able and interesting advocate of this last view.
 There are philosophers with discriminate views, who hold that there is a place and legitimate sphere for each faculty, and one must figure out what the limits are to each. Rene Descartes holds that reason is considerably more important than the senses in that reason provides more basic knowledge than the senses. It tells us about the essences of things, which the senses do not. Nonetheless, Descartes holds that the senses have a place in our scientific attempts to understand the world. Descartes also holds that various truths can only be determined by faith. John Locke also, seeks to determine the limits of human understanding, what we can know and why, what role the senses and reason play, and what can only be believed or taken as an article of faith. For Locke, the senses and reflection provide the materials on which reason works. Faith operates beyond reason. Another strand that caused the interest in knowledge was the extraordinary advances made during this period in mathematics and natural philosophy or science as we now call it. European mathematicians were finally able to surpass the results of the Greek mathematicians of antiquity such as Euclid and Archimedes. Similarly natural philosophers were coming to reject Aristotelian physics and Ptolemaic cosmology and geography. With the work of Copernicus, Brahe, Galileo and Kepler, placed astronomy and physics were new understructure. Surely, these extraordinary advances represented real knowledge. The struggle between sceptical arguments and scientific achievement, not to mention the claims of religion was a real one. One can see all, but these concern meeting in thinkers like Descartes and Pascal.
 Philosophers during this era were obsessed with methods for discovering and presenting truths. A method, in this context, supposes some systematic procedure, which, if followed, guarantees that one will hit upon the truth and avoid error. One source of this interest in method is Greek mathematics. Euclid's Elements of Geometry and the works of other ancient mathematicians provided a model of knowledge and proof. How was this wealth of mathematical knowledge discovered? The demonstration of the theorems does not seem to provide much insight in answering this question. So, mathematicians and philosophers in the fifteenth and sixteenth centuries began reflecting on the method of discovery that they called the method of analysis. Essentially the view that began to develop was that one would take apart the thing which one wished to understand, until one reached the basic and essential parts composing it. One would then analyse how the parts relate to one another and put them back together. By taking them apart in this way and then putting them back together one emerged with a new understanding.
 Galileo uses a method that he called the Resolution-Compositive method. The whole which one is studying got resolved into its parts and then put back together or composed again. This resolution into parts often involves simplifying and abstracting parts.
 Thomas Hobbes adopted this Galilean method to the study of man. Making the distinction between the complicated world in which there are good and bad, legitimate and illegitimate governments, and the state of nature in which there is no government is an exercise in the resolution of a whole into its parts. Once we see the nature of man in such a state, Hobbes thinks it becomes abundantly clear what the legitimate function of government is, however. We emerge from the exercise seeing clearly how to judge of the goodness and legitimatised governments from bad and illegitimate one’s. Locke and Spinoza, who both read Hobbes, perform similar analyses on the state, though with differing results. In the eighteenth century some analyses of the origins of language employ a similar method.
 Descartes was extraordinarily interested in method. He wrote works like The Discourse on Method and gives quite remarkable examples of discoveries in geometry and other subjects that he claims were made from the methods he describes. In John Cottingham's book The Rationalists you will find chapter two devoted to a discussion of these methods in the works of Descartes, Spinoza and Leibniz.
 Besides the method of analysis, Descartes is famous for employing what has become called the method of doubt in the Meditations to try to defeat skepticism. The method works like this. Descartes' puts forth a sceptical hypothesis concerning a certain class of his beliefs. (He does not want to doubt each belief individually as this would be impractical.) The classes that he generates turn out to be related to particular faculties, the senses, imagination and reason. He then tries to determine what can and what cannot be doubted by his sceptical hypothesis. If there are things that cannot be doubted on a particular sceptical hypothesis, he tries to generate a stronger sceptical hypothesis that will bring into doubt those things that could not be doubted on the previous hypothesis. Eventually, the application of this method leads him to the conclusion that there are a variety of things that cannot be doubted on the strongest possible sceptical hypothesis
 Descartes proposed a dualistic relation between the conscious, volitional soul, and the rest of the brain and body. The interface worked both ways, with (processed) sense information going into consciousness, and volition proceeding in reverse to operate the motor system. Descartes recognised that much of what we do could be explained by more direct links between sensory stimuli and the motor system, so the soul was not essential for all actions. One-way Cartesianism is the belief in a kind of Cartesian Dualism, but where the soul is purely passive, having knowledge of what passes in the brain, but no ability to initiate actions. It has the illusion of doing so, because from its privileged position it can see actions in preparation before they occur. The following passage from my Neurophysiology (3rd Edition, 1996; Arnolds, London) tries to explain the idea to a relatively general audience.
'Nothing puzzles me more than time and space.  Yet nothing troubles me less, as I never think about them'
 Charles Lamb's reaction is not very different from that of most neurophysiologists to problems of mind, brain, and consciousness. This is of course a field that has been thoroughly dug over since the days of Descartes and Hume and indeed long before: and philosophers have every right to question whether mere empirical physiologists can add much to such a hoary debate, in which the various arguments have been rehearsed so exhaustively. But recent developments both in neurophysiology and in computer science -for £20 I can purchase an electronic device hardly bigger than a packet of cigarettes, which is the intellectual superior of half the animal kingdom -have so enlarged our notions of what classes of operation a physical system may in principle be capable of, that a great deal of earlier thought on the subject is now merely irrelevant. In brief, 'brain versus mind' is no longer a matter for much argument. Functions such as speech and memory, which not so long ago were generally held to be inexplicable in physical terms, have now been irrefutably demonstrated as carried out by particular parts of the brain, and to a large extent imitable by suitably programmed computers. So far has brain encroached on mind that it is now simply superfluous to invoke anything other than neural circuits to explain every aspect of Man's overt behaviour. Descartes' dualism proposed some non-material entity -the 'ghost in the machine' -that was provided with sense data by the sensory nerves, analysed them within itself, and then responded with appropriate actions by acting on motor nerves (the mind thus having the same relation to the body as a driver to his car: But what about free will? The ghost in such a scheme would observe the body's actions being planned, and see the commands being sent off to the muscles before the actions themselves began, and so one can well imagine how it might develop the illusion that because it knew what was going to happen, that it was itself the cause. For X, the distinction between 'I lift my arms' and 'My arms go up', in which Wittgenstein epitomised the notion of voluntary action, would amount simply to the distinction between those actions that it observed being planned, and those -such as reflex withdrawal from a hot object -which it did not. There is no implied necessity here for us to be deterministic in our actions -to an outsider we may appear to have free will -since the physical processes linking S and R can be as random and essentially unpredictable as we please. Such a scheme seems more intellectually satisfying than (a) or (b) without conflicting with our own feelings about ourselves.  Unlike ©, does not merely evade the issue. The most serious objection to it is perhaps that it is difficult to see what on earth X is for, since it can't actually do anything. Perhaps it does just occasionally intervene. But in any case, what is the audience at a concert for? Or the spectators at a football match? The idea that I am being carried round by my body as a kind of perpetual tourist, a spectator of the world's stage, is not -on reflection -so very unattractive. René Descartes, the celebrated mathematician and physicist, is also often considered a founder of modern philosophy, as he sought new ways to move beyond Medieval Aristoteleanism and justify the science of his day. In his Discourse on Method he expresses his disappointment with traditional philosophy and with the limitations of theologies, only logic, geometry and algebra hold his respect, because of the utter certainty that they can offer us. Unfortunately, because they depend on hypotheses, they cannot tell us what is real (i.e., what the world is really like). Therefore Descartes proposes a method of thought incorporating the rigour of mathematics but based on intuitive truths about what is real, basic knowledge that could not be wrong (like the axioms of geometry). He calls into question everything that he thinks he has learned through his senses but rests his whole system on the one truth that he cannot doubt, namely, the reality of his own mind and the radical difference between the mental and the physical aspects of the world.
 Descartes (late in our excerpt) suggests that sense experience might be like dreaming, i.e., vivid but not matching the way things really are. But what does he realize must be the case even if his senses cannot be trusted?
 Good sense is the most evenly distributed thing in the world, for all people suppose themselves so well provided with it that even those who are the most difficult to satisfy in every other respect never seem to desire more than they have. It is not likely that everyone is mistaken, this attitude divulged upon the ability to judge and distinguish the truth from it’s the insincerity of falsehood, which is properly what one call’s good sense or reason, is in fact naturally equally distributed among all people. Thus the diversity of our opinions does not result from some of us being more reasonable than others, but solely from the fact that we conduct our thoughts along different paths, and consider different things . . . As far as reason--or good sense -is concerned, since it is the only thing that makes us human and differentiates us from the animals, I should like to believe that it is entirely present in each of us. . . .
 I was nourished by study from my earliest childhood.  Since I was convinced that this was the means to acquire a clear and certain knowledge of all that is useful in life, I had an extreme desire to learn. But as soon as I had finished a course of studies that usually culminates in one being accepted as one of the learned, I changed my opinion completely; for ‘I’ found myself troubled by so many doubts and errors that the only profit I had gained in seeking to educate myself was to discover ever more clearly the extent of my ignorance. Nevertheless I had been at one of the most famous schools in Europe, where I thought there must be wise men if such existed anywhere on earth. There I had learned all that the others learned.  Besides, not satisfied with the knowledge that we were taught, I had poured over all the unusual and strange books that I could lay my hands on. In addition, I knew how others evaluated me.  I did not want to be considered inferior to my fellow-students, even though some among them were already destined to take the places of my teachers. Finally, our century seemed to me to abound in as many wise spirits as any preceding one, which led me to suppose that I could judge the experience of others by my own, and to think that there was no such knowledge in the world such as I had been led to hope for . . .
 I was especially pleased with mathematics because of the certainty and clarity of its proofs; but I did not as yet realize its true usefulness; and, thinking that it was only useful in the mechanical arts, I was astonished that, since its foundations were so firm and solid, no one had built something higher upon it. To the contrary, I felt that the writings of who had discussed morality were likely superb, magnificent palaces that were built on mere sand and mud: they greatly praised the virtues and made them appear more exalted than anything else in the world; but they did they did not sufficiently teach how to know them. Often that which they called by the fine name of ‘virtue’ was nothing but apathy, or pride, or despair, or parricide.
 I revered our theology, and hoped as much as anyone else to get to heaven, however, having learned, as if it were certain, that the road to heaven is as open to the most ignorant as to the most learned, and that the revealed truths that lead one there are beyond our comprehension, I did not dare to submit them to my feeble reasoning, and I thought that to undertake successfully to examine them one would need some extraordinary, heavenly aid and beyond human ability.
 Of philosophy I will say nothing except that, seeing that it had been developed by the finest minds that had lived over many centuries and that nevertheless there was no point in it that was not still under dispute, and consequently doubtful, I lacked the presumption to hope that I would succeed any better than the others. When I considered how many different opinions there, had been about the same subject put forward by learned men, whereas only one of them could have been correct, I considered that anything that was only probable was as good as false . . .
 It is true that while I considered only the customs of other ordinary men, I found nothing in them to reassure me, and I noticed as much diversity among them as I had earlier done among the opinions of philosophers. The greatest benefit I received from this study was that, having observed many things that, while they seemed quite extravagant and ridiculous, were nevertheless commonly accepted as true and approved by great peoples, I learned not to believe too firmly in anything of which I had been persuaded only by example and custom. Thus I freed myself little by little from many errors that can dim our natural light and even make us less able to listen to reason. But after I had spent several years thus studying the book of the world and trying to get some experience, I one day resolved to study my own self, and to use all the powers of my mind to choose the path I should follow, which was much more successful, it seems to me, than if I had never left my country or my books.
 When I was younger, I had studied a little among other branches of philosophy, logic, and among types of mathematics, geometrical analysis and algebra: three arts or sciences that seemed as if they ought to contribute something to my goal. But when I examined them, I realized that as far as logic was concerned, its syllogisms and most of its other methods serve only to explain to someone else that which one already knows, or even, like Lully's art, to speak foolishly of things one does not know, rather than actually to learn anything. Even though logic contains, in fact, many very true and good precepts, they are nevertheless mingled with so many others that they become harmful or superfluous, that it is almost as hard to separate them out as to carve of Diana or a Minerva from as yet, the untouched block of marble. Besides, as far as the analysis of the ancients or modern algebra is concerned, and besides the fact that they can deal only with very abstract matters that seem utterly useless, the former is always so restricted to the study of geometrical figures that it cannot exercise the understanding without greatly tiring the imagination.  The latter is so restricted to certain rules and figures that it has become a confused, obscure art that perplexes the mind instead of being a science that cultivates it. So I thought that I had to look for some other method that, having the advantages of these three, would be free of their defects. Just as a multitude of laws often creates excuses for vices, so that the best regulated state is that which, having very few laws, makes those few strictly observed, instead of the great number or precepts that make up logic, I thought that the four following precepts would suffice, provided that I could make a firm, steadfast resolution not to violate them even once.
 The first was to never accept anything as true which I could not accept as obviously true; that is to say, carefully to avoid impulsiveness and prejudice, and to include nothing in my conclusions but whatever was so clearly presented to my mind that I could have no reason to doubt it.
 The second was to divide each of the problems I was examining in as many parts as I could, as many as should be necessary to solve them. The third, to develop my thoughts in order, beginning with the simplest and easiest to understand matters, in order to reach by degrees, little by little, to the most complex knowledge, assuming an orderliness among them, which did not at all naturally seem to follow one from the other. And the last resolution was to make my number carry through and into my ex post facto, as can be felt of me that I could be secure that for which I had not to leave out anything.
 These long chains of reasoning, so simple and easy, which geometers customarily used to make their most difficult demonstrations, caused me to imagine that everything which could be known by human beings could be deduced one from the other in the same way, and that, provided only that one refrained from accepting anything as true which was not, and always preserving the order by which one deduced one from another, there could not be any truth so abstruse that one could not finally attain it, nor so hidden that it could not be discovered. And I had little trouble finding which propositions I needed to begin with, for I already knew that they would be the simplest and the easiest to know. . . .  I took the best features of geometrical analysis and of algebra, and corrected all the defects of one by the other.
 I had noticed for a long time that it was necessary sometimes to agree with opinions about ethics that I knew to be quite uncertain, even though they were indubitable, as I said earlier, since I wanted to devote myself solely to the search for truth, I thought that I should act in the opposite manner, and reject as absolutely false anything about which I could imagine the slightest doubt, so that I could see if there would not remain after all that something in my belief that could be called absolutely certain. So, because our senses sometimes trick us, I tried to imagine that there was nothing that is the way that we imagine it.  Since there are people who are mistaken about the simplest matters of geometry, making mistakes in logic, and supposing that I was as likely to make mistakes as anyone else, I rejected as false all the reasoning that I had considered as valid demonstrations. Finally, considering that all our thoughts that we have when we are awake can also come to us when we are sleeping without a single one of them being true, I resolved to pretend that everything I had ever thought was no more true that the illusions in my dreams. But I immediately realized that, though I wanted to think that everything was false, it was necessary that of ‘me’ as the representation of who was doing the thinking was something that gave its resemblance to ‘I.’ Noticing that this truth -I think, therefore I am was so certain and sure that all the wildest suppositions of skeptics could not shake it, I judged that I could unhesitatingly accept it as the first principle of the philosophy for which I was seeking.
 Then, examining closely what I was, and seeing that I could imagine that I had no body and that there was no world or place where I was, I could not imagine that I did not exist at all. On the contrary, precisely because I doubted the existence of other things it followed obviously and certainly that I did exist. If, on the other hand, I had only ceased to think while everything else that I had imagined remained true, I would have had no reason to believe that I existed; therefore I realized that I was a substance whose essence, or nature, is nothing but thought, and which, in order to exist, needs no place to exist nor any other material thing. So this self, which is to say the soul, through which I am what I am, is entirely separate from the body, and is even more easily known than the latter, so that even if I did not have a body, my soul would continue to be all that it is.
 Descartes' first published work consists of three appendixes as follows: (A) La Dioptrique: This is a work on optics and his contribution is his approach through experimentation. Although Descartes does not cite previous scientists for the ideas he puts forward, the book does not consist of all new concepts.
 The chief focus of this book is given in the law of refraction. This appears to have been taken from Snell's work, though, unfortunately, it is put forward in a way, which might lead a reader to suppose that the law was a result of the researches of Descartes. Descartes would seem to have repeated Snell's experiments when in Paris in 1626 or 1627, and it is possible that he subsequently forgot how much he owed to the earlier investigations of Snell. A large part of the optics is devoted to determining the best shape for the lenses of a telescope, but the mechanical difficulties in grinding a surface of glass to a required form are so great as to render these investigations of little practical use. Descartes seems to have been doubtful weather to regard the rays of light as proceeding from the eye and so to speak touching the object, as the Greeks have had to be  perceived, that through which have so done, that they have practised authoritatively or as proceeding from the object, and so affecting the eye, least of mentions, that he considered the velocity of light to be infinite, although he did not deem the point particularly important.
(B) Les Météores; This is a work on meteorology and its importance is it being the first work, which attempts to conduct the study of weather on a scientific basis. It contains an explanation of numerous atmospheric phenomena, including the rainbow. Descartes was unacquainted with the fact that the refractive index of a substance is different for lights of different colours. Consequently, the explanation of the latter is necessarily incomplete. However many of Descartes' claims are not only wrong but could have easily been seen to be wrong if he had done some easy experiments. For example Roger Bacon had demonstrated the error in the commonly held belief that water, which has been boiled, freezes more quickly. However Descartes claims, . . . and we see by experience that water that has been kept on a fire for some time freezes more quickly than otherwise, the reason being that those of its parts that can be most easily folded and bent are driven off during the heating, leaving only those that are rigid. Despite its many faults, the subject of meteorology was set on course after publication of Les Météores. La Géométrie; This is by far the most important part of this work. The book is further divided into three books: the first two of these treat of analytical geometry, and the third includes an analysis of the algebra then current.
 The first book commences with an explanation of the principles of analytical geometry, and contains a discussion of a certain problem, which had been propounded by Pappus in the seventh book of his and of which some particular cases had been considered by Euclid and Apollonius. The general theorem had baffled previous geometricians, and it was in the attempt to solve it that Descartes was led to the invention of analytical geometry. The full enunciation of the problem is rather complicated, but the most important case is to find the locus of a point such that the product of the perpendiculars on m given straight lines will be in a constant ratio to the product of the perpendiculars on n other given straight lines. The ancient geometricians had solved this geometrically for the case m = 1, n = 1, and the case m = 1, n = 2. Pappus had further stated that, if m = n = 2, the locus is a conic, but he gave no proof; Descartes also failed to prove this by pure geometry, but he showed that the curve can be represented by an equation of the second degree, that is, a conic.
 In the second book Descartes divides curves into two classes, namely, geometrical and mechanical curves. He defines geometrical curves as those that can be generated by the intersection of two lines each moving parallel to one co-ordinate axis with ‘commensurable’ velocities; by which terms he means that dy/dx is an algebraical function, as, for example, is the case in the ellipse and the cissoid. He calls a curve mechanical when the ratio of the velocities of these lines is ‘incommensurable’; by which term he means that dy/dx is a transcendental function, as, for example, is the case in the cycloid and the quadratrix. Descartes confined his discussion to geometrical curves. Descartes also paid particular attention to the theory of the tangents to curves -as perhaps might be inferred from his system of classification just alluded to. The then current definition of a tangent at a point was a straight line through the point such that between it and the curve no other straight line could be drawn, that is, the straight line of closest contact. Descartes proposed to substitute for this a statement equivalent to the assertion that the tangent is the limiting position of the secant; Fermat, and at a later date Maclaurin and Lagrange, adopted this definition. Barrow, followed by Newton and Leibnitz, considered a curve as the limit of an inscribed polygon when the sides become indefinitely small, and stated that the side of the polygon when produced became in the limit a tangent to the curve. Roberval, on the other hand, defined a tangent at a point as the direction of motion at that instant of a point that was describing the curve. The results are the same whichever definition is selected, but the controversy as to which definition was the correct one was none the less lively. In his letters’ Descartes illustrated his theory by giving the general rule for drawing tangents and normals to roulette.
 The method used by Descartes to find the tangent or normal at any point of a given curve was substantially as follows. He determined the centre and radius of a circle, which should cut the curve in two consecutive points there. The tangent to the circle at that point will be the required tangent to the curve. In modern textbooks it is usual to express the condition that two of the points in which a straight line (such as y = mx + c) cuts the curve will coincide with the given point: this enables us to determine m and c, and thus the equation of the tangent there is determined. Descartes, however, did not venture to do this, but selecting a circle as the simplest curve and one to which he knew how to draw a tangent, he so fixed his circle as to make it touch the given curve at the point in question, and thus reduced the problem to drawing a tangent to a circle. However, he only applied this method to curves, which are symmetrical about an axis, and he took the centre of the circle on the axis.
 The third book of the Géométrie contains an analysis of the algebra. The influence of the book is that it has affected the language of the subject by fixing the custom of employing the letters at the beginning of the alphabet to denote known quantities, and those at the end of the alphabet to denote unknown quantities. This was a further development toward the development of algebraic notations. In addition, Descartes also invented the system of indices (e.g., in x2, x3, x4 . . . ) to express the powers of numbers, which are now widely used. It is doubtful whether or not Descartes recognized that his letters might represent any quantities, positive or negative, and that it was sufficient to prove a proposition for one general case. He was the earliest writer to realize the advantage to be obtained by taking all the terms of an equation to one side of it. He realized the meaning of negative quantities and used them freely. In this book he made use of the rule, which is known as Descartes’ rule of signs, for finding the limit to the number of positive and of negative roots of an algebraical equation, and introduced the method of indeterminate coefficients for the solution of equations. He believed that he had given a method by which algebraical equations of any order could be solved, but in this he was mistaken.
 In a book named The Scientific Work of René Descartes (1987), J.F. Scott summarizes the importance of this work in four points, (I) -He makes the first step toward a theory of invariants, which at later stages derelativises the system of reference and removes arbitrariness. (ii). Algebra makes it possible to recognise the typical problems in geometry and to bring together problems that in geometrical dress would not appear to be related at all.
(iii). Algebra imports into geometry the most natural principles of division and the most natural hierarchy of method.
(iv) Not only can questions of solvability and geometrical possibility be decided elegantly, quickly and fully from the parallel algebra, without it they cannot be decided at all.
 René Descartes (1596-1650) is primarily associated with Philosophy his Discourse on Method and Meditations have even led him to be called the ‘Father of Modern Philosophy.’ In his most celebrated argument, Descartes attempted to prove his own existence via the now hackneyed argument, ‘I think therefore I am.’ However, it should not be forgotten that René Descartes applied his system to investigations in physics and mathematics, with real success, playing a crucial role in the development of a link between algebra and geometry -now known as analytic geometry, a subject defined by Webster's New World Dictionary as ‘the analysis of geometric structures and properties principally by algebraic operations on variables defined in terms of position coordinates.’ Simply put, analytic geometry translates problems of geometry into ones of algebra. Before the Cartesian plane and analytic geometry, most mathematicians considered (synthetic) geometry and (diophantine) algebra to be two different fields of study. To anyone that has taken a high school course in analytic geometry, that notion seems ridiculous, or even incomprehensible, but to mathematicians of 500 years ago or more, solving geometric problems using the methods of algebra probably seemed equally absurd.
 In fact, as will be evident later in the paper, much of our tenth grade ‘vocabulary’ (using x2 to represent the equation of a parabola, using terms ‘a’, ‘b’, ‘c’, to be an indication of indeterminate parameters, etc. . . . ) can trace their roots directly back to the work o f René Descartes, building on the algebra of the late 16th century.
 How did it happen that someone who had more interest in determining whether or not we live in a dream world than in, for example, determining the mean and extreme ratio mathematically, come fundamentally to change not only the way we do geometry, but also the way we think about geometry? To understand the answer, it will be useful to examine the life of René Descartes and the period in which he flourished.
 Descartes' father was a lawyer and judge, and his parents belonged to the noblesse de robe, the social class of lawyers, between the bourgeoisie and the nobility. As such he received and excellent education, and had the financial resources to continue his studies at the Jesuit College of the town of La Flhche in Anjou. Men are a product of their times, and René Descartes was no exception. After hearing that Galileo Galilei, among others, both pronounced, and persuasively argued, that the sun did not revolve around the Earth, but rather vice versa, and that, in addition, the earth made a complete revolution daily, Descartes began to question whether any of the senses could be trusted as a source of information. After all, his sense of motion clearly demonstrated that the Earth is stationary, while it was ‘truly’ rotating and moving at a great speed through space. If his senses could be wrong in regard to something so basic, was not it possible to be equally mis taken in other fundamental areas as well? Nonetheless, according to Descartes ‘I concluded that I might take as a rule the principle that all things that we very clearly and obviously conceive are true: only observing, however, that there is some difficulty in rightly determining the objects that we distinctly conceive.’ Descartes held knowledge up to a very severe standard. According to Descartes, the four rules of logic were: (1) To accept as true only those conclusions that were clearly and distinctly known to be true.
(2) To divide difficulties under examination into as many parts as possible for their better solution. (3) To conduct thoughts in order, and to proceed in stages from the simplest and easiest to know, to more complex knowledge. (4) In every case to take a general view so as to be sure of having omitted nothing.
 Because of his severe standard, Descartes' quest for underlying truths blossomed into a distinct penchant for mathematics, where proofs were just that -undeniable knowledge. Descartes' fourth standard conveys more than just a hint of the mathematician as well as the philosopher. Often in mathematics, solving a simple problem can be trivial. However, the formulation of a general rule to solve the problem can be infinitely more useful. Descartes seems to say in his fourth rule that the general case is the one of great importance, not the specific problem. Eventually Descartes published his ideas in a little book, or appendix, titled La Géomitrie, in 1637. Descartes major contribution in this book is considered to lie in the idea of a coordinate system, allowed problems that were considered to be strictly geometric to pass over into algebra. Although the association of algebra and geometry was proposed even by the Greeks, and taken up anew as a program by Vihte, no satisfying procedure had been found to merge the two disciplines into one ( until the development of the Cartesian plane. Thus, Descartes was not the first to attempt to develop a coordinate plane, but his method has been the one that achieved the desired goal. Both the Greeks and Egyptians had developed a numerical coordinate system (driven by its relevance to astronomy and cartography), but with little mathematical development. ‘Hipparchus (Bc. , 150) and Ptolemy (150 AD.), to name but two, both employed a system of latitude and longitude to locate stars on the celestial sphere. The Greeks even employed a system that made use of two axes at a right angle. However, nothing systematic or permanent came out of the study of specific problems using two axes as part of the solution. Heath says that ‘the essential difference between t he Greek and modern method is that the Greeks did not direct their efforts to making the fixed lines of a figure as few as possible, but rather to expressing their equations between areas in as short and simple a form as possible. The first real development of a geometrical coordinate system comes in the work of Apollonios of Perga Apollonios of Perga, or the ‘Great Geometer’ as he was known, wrote a book called Conics, which, among other things, introduced the world to the terms parabola, ellipse, and hyperbola. In his Conics, Apollonius used a system of coordinates to solve problems regarding second-order curves (conic sections). The next person significantly to advance the creation of the coordinate system was Frangois Vihte (1540-1603). In his In Artem analyticem Isagoge (Introduction to the Analytical Art) published in 1591, Vihte announced a program to ‘[bring] together the ancient geometrical methods of Euclid, Archimedes, Apollonius, and Pappus, with ancient algebraic methods to produce his logistica speciosa, a way to formulate and solve algebraic problems. Among other things, this text uses consonants to represent given quantities and vowels to denote unknown quantities. This led to Vihte's nickname, The father of modern algebra. The degree of Descartes' originality remains a subject of controversy, as will be addressed at greater length below, a controversy that has persisted in the three and some half centuries since his death.
 In Descartes' La Géomitrie, he uses the letters ‘a’, ‘b’, ‘c’, etc., to express of the acknowledged magnitudes and ‘x’, ‘y’, ‘z’, for unknown ones. Later on, Descartes unveils what appears to be the birth of a fixed set of coordinate systems in a passage beginning, ‘Let AB, AD, EF, GH,  . . . be any number of straight lines given in position . . . Smith points out here ‘it should be noted that these lines are given in position but not in length. They thus become lines of reference or coordinate axes, and accordingly they play a very important part in the development of analytic geometry. In this connection we may quote as follows: 'Among the predecessors of Descartes we reckon, besides Apollonius, especially Vihte, Oresme, Cavalieri, Roberval, and Fermat, the last the most distinguished in the field; yet, it seems that there may be not anywhere, even by Fermat, had any attempt been made to refer several curves of different or de-simultaneously to one system of coordinates, which at most possessed special significance for one of the curves. It is exactly this thing that Descartes systematically accomplished. However, Scott does not agree with this assessment, as will be seen below. Another person who played a key role in the creation of analytic geometry was Pierre Fermat (1601 -1665), although it is unclear whether or not Descartes knew of Fermat's work (the subject for which we will return), Ad Locos Planos et Solidos Isagoge. In an effort to recover some of the lost proofs of Apollonius, Fermat used a system of coordinates to refer to various curves. There was a large advance in the use of the coordinate system between Apollonios and Fermat. ‘In [Fermat's] published works, too, there is incontrovertible evidence that he had hit upon the idea of expressing the nature of curves by means of algebraic equations. How clearly in fact, he had grasped the fundamental principles of analytic geometry becomes evident after a study of the opening pages of the Isagoge, the substance of which is as follows: 'Whenever two unknown quantities are found in a final equation we have a locus and the extremity of one of them describes a right angle line or a curve.
 The straight line is simple and unique; the curves are infinite in number and embrace the circle, parabola, ellipse, etc.  . . . Fermat goes on to list various equations of geometric interest, such as the equation of a straight line through the origin (x/y = b/d), the equation of any straight line (b/s = (a-x)/y), the equation of certain types of circle (a2-x2=y2), the equation of certain types of ellipse (a2-x2=ky2), and the equations of certain types of hyperbola (a2+x2=ky2). These formulas should leave no doubt that Fermat understood the underlying principles of analytical geometry, and helped lay the foundation for its development. The ideas with which La Géomitrie had to deal, at least potentially, were of three types according to the formulation of J.F. Scott. (1) The employment of coordinates as a mere instrument of description (2). Algebra and geometry collaborate on single problems (3). Transference of system and structure by analysing these individually we can see how influential they were in the development of analytic geometry, and consider more carefully which of them are actually attributable to Descartes, according to Scott. The first item, according to Scott, constitutes the most visible connection between Descartes' work and the Cartesian plane. In La Géomitrie, Descartes uses a system of coordinates adapted to each problem. When studying multiple curves, he uses a system of lines to unify all the separate coordinate systems into one giant system. This account clashes with the opinion of Fink and Smith, according to whom Descartes' coordinate system was set up in advance for a general set of curves, not a particular one. As far as the second point, it is the most important in Descartes' work. Using algebra to solve geometric problems greatly enhanced the flexibility of geometry. This became a legitimate way to solve a problem, and as is often found in mathematics, the m ore ways there are to approach a class of problems, the better. An example of this given at the outset in La Géomitrie was the solution of a problem of Pappus, which Descartes claimed had not been completely solved by anyone.
 In a letter to his friend Mersenne, Descartes wrote, ‘J'risous un e question qui par le timoignage de Pappus n', estre trouvie par qucun des Ancient, et l'on peut dire qu'elle ne l'a p estre non plus par aucun des Modernes.’ (‘I solve a problem that defeated the ancients and the moderns alike.’) Pappus' problem reads, ‘There being three, or four, or a greater number of right lines given in position in a plane, it is first required to find the position of a point from which we can draw as many other right lines, one to each of the given lines, making a known angle with it, such that the rectangle contained by two of these drawn from this point has a given proportion either to the square on the third, if there are only three, or to the rectangle contained by the other two, if there are four. Or if there are five, the product of the remaining two lines so drawn has a given proportion to the product of the remaining two and another line, and so on.’.
 Descartes originally attempted to solve this problem using pure geometry, and was unable to. This aided Descartes in his pursuit to find another method to solve the problem. Using his newly developed analytic methods, Descartes wrote in a letter to his friend that he was able to solve the problem in just five or six weeks. Unsurprisingly, Sir Isaac Newton was the first one to solve these problem using methods of pure geometry. As to the third point that Scott raises in regard to the major achievements in La Géomitrie, it appears to be rather similar to the second, and possibly not necessary. As Scott puts it, ‘The structure of a whole region of geometrical theory is transferred to a region of algebraical theory, where it brings about an instructive rearrangement of the matter and raises algebraical problems that otherwise might not have imposed them.’
 Among the achievements of La Géomitrie, there are many methods that are still used today. Descartes proposes a method of simultaneously handling several unknown quantities at once. Also introduced is a clearer distinction between real and imaginary root s, which helped lead to modern mathematics. Scott also says, ‘It is momentously liberated, as when Descartes throws aside the dimensional restrictions of [Vihte] and lets the arithmetical second power a2 measure a length as well as an actual square, and the arithmetical first power a measure a square as well as an actual length.’
 In La Géomitrie, Descartes views curves of degree 2n and 2n-1 as having the same complexity, and thus as closely related. Scott even claims, Descartes notes, that this number is independent to the choice of organic coordinates. In modern ordinary language it is an invariant under change of axes. Here is a first case of invariance, when employing coordinates we are forced to make an arbitrary choice of axes and even of the type of coordinates, and in this way we impart an arbitrary element into our methods. Scott summarized the work of Descartes in of the priorates stating that what is done by a summarized mark of four mindfully employed headings: (1) He makes the first step toward a theory of invariants, which at later stages derelativises the system of reference and removes its arbitrariness. (2) Algebra makes it possible to recognize the typical problems in geometry and to bring together problems that in geometrical dress would not appear to be related at all. (3) Algebra imports into geometry the most natural principles of division and the most natural hierarchy of method. (4) Not only can questions of solvability and geometrical possibility be decided elegantly, quickly and fully from the parallel algebra, without it they cannot be decided at all. Much of the work that is thus accredited to René Descartes is the subject of controversy. His reputation came under attack while he was alive, attacks that have been renewed in the 350 years since his death. Even at the time of his publication of La Giomitrie, Descartes was forced to defend himself against claims that the work was in large part derived from the work of Pierre de Fermat and Frangois Vihte.
 There is no doubt that Fermat compiled his work in 1629, eight years before Descartes published La Géomitrie. However, this work of Fermat did not appear in print until 1679 (posthumously, in Opera Varia), approximately thirty years after Descartes' death. The question then is whether or not Descartes had access to his fellow countryman's compilation before it being published. Fermat gave his papers to M. Despagnet around 1629, but it is unclear whether or not Despagnet circulated these works further. Descartes did not remain silent about such allegations. He vehemently defended himself, saying even that he had nothing to learn from his contemporary mathematicians, because they were unable to solve the ancient problems. And in particular he [Descartes] leaves his readers in no doubt that he did not rate the achievements of Fermat very highly.’
 One may wonder whether maybe the opposite was true: could Fermat have ‘borrowed’ from Descartes? This possibility can be excluded. According to Scott, who appears to be a partisan of Descartes, Fermat's letters revealed his character to be of the highest moral caliber. One may also argue that had Fermat been familiar with Descartes' work.  He would likely have adopted Descartes' notation, far superior to his own. There is in any case no evidence that Fermat ever saw Descartes' work before its publication, much less before his own work in 1629, nor were any such allegations ever made. Scott comes to the conclusion that ‘It seems possible, therefore, that Descartes and Fermat had each made considerable progress in the new methods unconscious of what had been achieved by the other. He asserts that history has numerous examples of discoveries of great importance that were made simultaneously and independently. Frangois Vihte was another mathematician whom Descartes has been accused of robbing. In Vihte's book called, In Artem analyticem Isagoge, (1591), he uses a notational system to represent algebraic equations similar to the one employed by Descartes in La Géomitrie. T his has led to speculation that much of Descartes' accomplishments were merely restatements of work Vihte had done 45 years earlier. ‘But Descartes' clumsy cosec notation, derived in all probability from Clavius' (a 16th and 17th century teacher at the Jesuit Collegio Romano in Rome) Algebra, which he had studied while in college, indicates that he was not familiar with Vihte's work at this point, for Vihte's notation is clearly superior, and had he been familiar with it he could not have favoured that of Clavius. Descartes was obliged to rediscover these relations, to formulate the problems in his own terms, and to develop his own uniformity implied through the so-called I-ness, that he had only of himself to cause in solving the problem, something he was to do in a way that went far beyond Vihte's pioneering work. On the other hand, had Descartes wanted to take credit for another's ideas, it is doubtful that he would have been so overt as blatantly to copy Vihte's notation. In this regard, Descartes wrote, ‘As to the suggestion that what I have written could easily have been gotten from Vihte, the very fact that my treatise is hard to understand is due to my attempt to put nothing in it that I believed to be known by either him or anyone else . . . I begin the rules of my algebra with what Vihte wrote at the very end of his book, De emendatione aequationum . . .  This does of course openly acknowledge familiarity with Vihte.
 One final person declared Descartes, which on no any uncertain terms  are thought of a plagiarist -John Wallis (1616-1703). Wallis repeatedly and very publicly said that the main principles of coordinate geometry had already been published in Artis Analyticf Praxis by Thom as Harriot (1560-1621). Wallis wrote in Algebra (1685), a treatise designed to promote the ideas of Harriot, which were first published in 1631, that ‘Harriot hath laid the foundation on which Des Cartes hath built the greatest part of his Algebra or Geometry.’
 ‘While there appears little doubt that Descartes did not hesitate to avail himself of the knowledge of Harriot in his treatment of equations, it is difficult to find anything in Harriot's published works to suggest that he had devoted any attention to the subject of coordinate geometry.’
 How René Descartes came up with the ideas, presented in his La Géomitrie is unclear. What is clear is that regardless of the source of these ideas, La Géomitrie is a work of great importance that fuelled the adoption of the Cartesian plane and the development of analytic geometry, allowing problems of geometry to be solved by algebraic methods.
 It seems only fitting to end this paper, but the way Descartes ended his La Géomitrie -with a little humour and more than a little arrogance. ‘Et i'espere que nos neueux me sgauront gri, non seulement des choses que iay icy expliquies; mais aussy de celes que iay omises volontairemen [sic], affin de leur laisser le plaisir de les inuenter.’ Or as David Eugene Smith and Marcia L. Latham have it: ‘I hope that posterity will judge me kindly, not only as to the things that I have explained, but also as to those that I have intentionally omitted so as to leave to others the pleasure of discovery.’
 ‘I do not believe that there exists anything in external bodies for exciting tastes, smells, and sounds, etc. except size, shape, quantity, and motion.’ When Galileo proposed his doctrine of subjectivity and objectivity, as their distinction between primary and secondary qualities, was established by scientific prejudgement, in that the conceptual representation be of space, it was something geometrical and not differentiated qualitatively.
 Newtonian ‘absolute space’ was based on a realist conception of mathematics. To Newton, mathematics, particularly geometry, is not a purely hypothetical system of propositions . . . instead geometry is nothing but a special branch of mechanics. Newton's first law of motion, which links change in motion with force requires an absolute (or inertial?) framework. It requires a distinction between absolute motion and relative motion and links force to a change in absolute motion. For example, as the train pulls away from the station, the station may appear to be moving and it can be said that the station is in relative motion to the train, but the force is acting upon the train, and it is the train that is accelerating absolutely. Newton tried to establish an absolute frame of reference for the universe defined in relation to its centre of gravity. (Not necessarily identical with the sun) Absolute spatial movement and position could then be measured in relation to that point.
 But is geometry an empirical or ideal activity? For Cassirer, the most radical removal of geometry from experience had already occurred with Euclid, which was already based on figures that are removed from all possibilities of experiment. Not only the idealizations of point, line, and plane, but the idea of similar triangles, whose differences are considered inconsequential or fortunate, and become identified as the same mark, to be as respectably lacking form ordinary perception.
 The mathematization of space and its representations in Cartesian grids allowed space to become more abstract and less tied to a specific set of conditions. If the axes of the grid could stand for any set of variables, then a proliferation of types could take place. But even as Descartes' discovery of analytic geometry gave the problem of space an entirely new orientation, his own metaphysics describes space as some sort of absolute thing in the form of an extended substance, not simply a certain pattern of order.
 ‘In all the history of mathematics there are few events of such immediate and decisive importance for the shaping and development of the problem of knowledge as the discovery of the various forms of non-Euclidean geometry.’ In Euclidean geometry, the axiom of the parallels states that through a given point there is one and only one parallel to a given straight line that does not go through the given point. Non-Euclidean geometry starts with the opposite axiom  . . . When Riemann published ‘On the Hypotheses Underlying Geometry’ (1868) the axioms of Euclid, which had been regarded for centuries as the supreme example of eternal truth, now seemed to belong to an entirely different kind of knowledge. For Cassirer, ‘the whole problem of the truth of mathematics, even of the meaning of truth itself, was placed in an entirely new light. Until that time, both rationalist and empiricist philosophers had agreed that the relations of mathematical ideas were rigorously necessary and unalterable. How could entirely different and wholly incongruous systems of geometry uphold the claims of truth? ‘To recognize a plurality of geometries seemed to mean renouncing the unity of reason, which is its intrinsic and distinguishing feature.’
 ‘Mathematicians appropriated space and time, and made them part of their domain, yet they did so in a rather paradoxical way. They invented spaces: non-Euclidean spaces, curved spaces, – dimensional spaces, abstract spaces (such as phase space), and so on. For example, Gerald Edelman uses the concept of a n-dimensional neural space of all potential qualia, that includes every possible discrimination between states of consciousness. For Edelman, the dimensions of this space are given by the activity of actual groups of neurons in the brain.
 In this way, space became a ‘mental thing’ Physicists, according to Rudolf Carnap are free to choose among spatial systems according to their own requirements. He quotes Henri Poincaré's observation that no matter what observational facts are found, the physicist is free to ascribe to physical space any one of the mathematically possible geometrical structures, provided that he makes suitable adjustments in the laws of mechanics and optics and consequently in the rules for measuring. For Poincaré, ‘The object of geometry is the study of a definite group, but the general idea of the group preexists, at least potentially, in our mind, having forced itself not as a form of sensibility but as a form of our understanding. All we have to do is choose among all possible groups the one that will constitute a standard for us, as it were, to which natural phenomena are referred. Experience guides us in this choice but does not dictate it; nor does it permit us to know which geometry is truer but only which is more 'useful.'
 Rudolf Carnap rejects Kant's claim that geometry is a priori and synthetic. He splits geometry into mathematical geometry that is a priori because analytic and physical geometry that is synthetic and not a priori. In physics the choice of geometries becomes a pragmatic one. In his Philosophy of Space and Time, Hans Reichenbach develops this empiricist conception of geometry.
 Ernst Cassirer shows Poincaré's assessment of the impact of non-Euclidean geometry as a shift in the meaning of mathematical axioms. For Cassirer, the theory of sets had shown that the different geometries were all equally true in an ideal and mathematical sense. Geometry could be defined as a theory of invariants in respect to a certain group -only properties that are characterized by an invariance with respect to certain transformations can be called ‘geometrical.’ While Euclidean geometry applies to a ‘basic set’ of rigid bodies that are freely movable in space without changing form, different transformations can be applied to different sets of objects (defined as the ‘same,’ with respect to a particular criterion) For Cassirer, the modern sense of axioms differs from the ancient. Axioms are no longer assertions about content that have absolute certainty. Rather they are proposals of thought that make it ready for action.
 One thing that happened during the Renaissance that was of great importance for the later character of modern philosophy was the birth of modern science. Even as in the Middle Ages philosophy was often thought of as the ‘handmaiden of theology,’ modern philosophers have often thought of their discipline as little more than the ‘handmaiden of science.’ Even for those who haven't thought that, the shadow of science, its spectacular success and its influence on modern life and history, have been hard to ignore.
 For a long time, philosophers as diverse as David Hume, Karl Marx, and Edmund Husserl have seen the value of their in work in the claim that they were making philosophy ‘scientific.’ Those claims should have ended with Immanuel Kant (1724-1804), who for the first time clearly provided a distinction between the issues that science could deal with and those that it couldn't, but since Kant's theory could not be demonstrated the same way as a scientific theory, the spell of science, even if it is only through pseudo-science, continues.
 The word ‘science’ itself is simply the Latin word for knowledge: scientia. Until the 1840's what we now call science was ‘natural philosophy,’ so that even Isaac Newton's great book on motion and gravity, published in 1687, was The Mathematical Principles of Natural Philosophy (Principia Mathematica Philosophiae Naturalis). Newton was, to himself and his contemporaries, a ‘philosopher.’ In a letter to the English chemist Joseph Priestley written in 1800, Thomas Jefferson lists the ‘sciences’ that interest him as, ‘botany, chemistry, zoology, anatomy, surgery, medicine, natural philosophy [this probably means physics], agriculture, mathematics, astronomy, geography, politics, commerce, history, ethics, law, arts, fine arts.’ The list begins on familiar enough terms, but we hardly think of history, ethics, or the fine arts as ‘sciences’ anymore. Jefferson simply uses to the term to mean ‘disciplines of knowledge.’
 Something new was happening in natural philosophy, however, and it was called the nova scientia, the ‘new’ knowledge. It began with Mikolaj Kopernik (1473-1543),  whom of which has in being born to a Polish name given to us in calling him Latinized to Nicolaus Copernicus. To ancient and mediaeval astronomers the only acceptable theory about the universe came to be that of egocentrism, that the Earth is the centre of the universe, with the sun, moon, planets, and stars moving around it. But astronomers needed to explain a couple of things: why Mercury and Venus never moved very far away from the sun--they are only visible a short time after sunset or before sunrise--and why Mars, Jupiter, and Saturn sometimes stop and move backwards for a while (retrograde motion) before resuming their forward motion. Believing that the heavens were perfect, everyone wanted motion there to be regular, uniform, and circular. The system of explaining the motion of the heavenly bodies using uniform and circular orbits was perfected by Claudius Ptolemy, who lived in Egypt probably during the reign of the Emperor Marcus Aurelius (161-180). His book, still known by its Arabic title, the Almagest (from Greek Tò Mégiston, ‘The Greatest’), explains that the planets are fixed to small circular orbits (epicycles) which they are fixed to the main orbits. With the epicycles moving one way and the main orbits the other, the right combination of orbits and speeds can reproduce the motion of the planets as we see them. The only problem is that the system is complicated. It takes something like 27 orbits and epicycles to explain the motion of five planets, the sun, and the moon. This is called the Ptolemaic system of astronomy.
 Copernicus noticed that it would make things much simpler (Ockham's Razor, that entia non sunt multiplicanda praeter nercessitatem: entities are not to be multiplied beyond necessary: A watchword for many reductionist and nominalistic philosophers)  if the sun were the centre of motion rather than the earth. The peculiarities of Mercury and Venus, not explained by Ptolemy, now are explained by the circumstance that the entire orbits of Mercury and Venus are inside the Earth's orbit. They cannot get around behind the Earth to be seen in the night sky. The motion of Mars and the other planets is explained by the circumstance that the inner planets move faster than the outer ones. Mars does not move backwards; it is simply overtaken and passed by the Earth, which makes it look, against the background, as though Mars is moving backwards. Similarly, although it looks like the stars move once around the Earth every day, Copernicus figured that it was just the Earth that was spinning, not the stars. This was the Copernican Revolution. : Now this all seems obvious. But in Copernicus's day the weight of the evidence was against him. The only evidence he had was that his system was simpler. Against him was the prevailing theory of motion. Mediaeval physics had us to believe that motion was caused by ‘impetus.’ Things are naturally at rest. Impetus makes something move, than is less than quantified of some stretchability, leaving out the object to slow and come to rest. Something that continues moving therefore has to keep being pushed, and pushing is something you can feel. (This was even an argument for the existence of God, since something big-like God-had to be pushing to keep the heavens going.) So if the Earth is moving, why don't we feel it? Copernicus could not answer that question. Neither was there an obvious way out of what was actually a brilliant prediction: If the stars did not move, then they could be different distances from the earth.  As the earth moved in its orbit, the nearer stars should appear to move back and forth against more distant stars. This is called ‘stellar parallax,’ but unfortunately stellar parallax is so small that it was not observed until 1838. So, at the time, supporters of Copernicus could only contend, lamely, that the stars must all be so distant that their parallax could not be detected. Yeah, sure.
 Copernicus was also worried about getting in trouble with the Church. The Protestant Reformation had started in 1517, and the Catholic Church was not in any mood to have any more of its doctrines, even about astronomy, questioned. So Copernicus did not let his book be published until he lay dying.
 The answers, the evidence, and the trouble for Copernicus's system came with Galileo Galilei (1564-1642). Galileo is important and famous for three things: (1) Most importantly he applied mathematics to motion. This was the real beginning of modern science. There is no math in Aristotle's Physics. There is nothing but math in modern physics books. Galileo made the change. It is inconceivable now that science could be done any other way. Aristotle had said, simply based on reason, that if one object is heavier than another, it will fall faster. Galileo tried that out and discovered that Aristotle was wrong. Aerodynamics aside, everything falls at the same rate. But then Galileo determined what that rate was by rolling balls down an inclined plane (not by dropping them off the Leaning Tower of Pisa, which is the legend). This required him to distinguish between velocity (e.g., metres per second) and acceleration (change in velocity, e.g., metres per second per second). Gravity produced an acceleration-9.8 metres per second per second. Instantly Galileo had an answer for Copernicus: simple velocity is not felt, only acceleration is. So the earth can be moving without our feeling it. Also, velocity does not change until a force changes it. That is the idea of inertia, which then replaced the old idea of impetus. All this theory was ultimately perfected by Isaac Newton (1642-1727). (2) With the objections to Copernicus's theory removed, the case was completed with positive evidence. Around 1609 it was discovered in the Netherlands that putting two lenses (which had been used since the 13th century as eye glasses) together made distant objects look close. Galileo heard about this and he produced the first astronomical quality telescope. With his telescope he saw several things: (1) the Moon had mountains and valleys. This upset the ancient notion that the heavens, including the Moon, which was completely unlike the Earth. (2) The Planets all showed disks and were not points of light like stars. (3) Jupiter had four moons. This upset the argument, which had been used against Copernicus, that there could only be one centre of motion in the universe. Now there were three (the Sun, Earth, and Jupiter). (4) There were many more stars in the sky than could be seen with the naked eye. The Milky Way, which was always just a glow, was itself composed of stars. And finally (5) Venus went through phases like the Moon. That vindicated Copernicus, for in the Ptolemaic system Venus, moving back and forth at the same distance between the Earth and the Sun, would only go from crescent too crescent. It would mostly have its dark side turned to us. With Copernicus, however, Venus goes around on the other side of the Sun and so, in the distance, would show us a small full face. As it comes around the Sun toward the Earth, we would see it turn into a crescent as the disk grows larger. Those are the phases, from small full too large crescent, that Galileo saw. The only argument that could be used against him was that the telescope must be creating illusions. In fact it was not well understood why a telescope worked. Some people looked at stars and saw two instead of one. That seemed to prove that the telescope was unreliable. Soon it was simply accepted that many stars are double. They still are. (3) With his evidence and his arguments, Galileo was ready to prove the case for Copernican astronomy. He had the support of the greatest living astronomer, Johannes Kepler (1571-1630), but not the Catholic Church. He had been warned once to watch it, but then a friend of his became Pope Urban VIII (1623-1644). The Pope agreed that Galileo could write about both Ptolemaic and Copernican systems, setting out the arguments for each. Galileo wrote A Dialogue on the Two Principal Systems of the World (1632). Unfortunately, the representative of the Ptolemaic system in the dialogue was made to appear foolish, and the Pope thought it was a caricature of himself. Galileo was led before the Inquisition, ‘shown the instruments of torture,’ and invited to recant. He did, but was kept under house arrest for the rest of his life. Nevertheless, it was too late. No serious astronomer could ever be a geocentrist again, and the only discredit fell against the Church.
 Descartes is justly regarded as the Father of Modern Philosophy. This is not because of the positive results of his investigations, which were few, but because of the questions that he raised and problems that he created, problems that have still not been answered to everyone's satisfaction: particularly the Problem of Knowledge and the Mind-Body Problem. And in a day when philosophy and science were not distinguished from each other, Descartes was a famous physicist and mathematician as well as a philosopher. Descartes' physics was completely overthrown by that of Newton, so we do not much remember him for that. But Descartes was a great mathematician of enduring importance. He originated analytic geometry, where all of the algebra can be given geometrical expression. Like Galileo combining physics and mathematics, this also combined two things that had previously been apart, arithmetic and geometry. The modern world would not be the same without graphs of equations. Rectangular coordinates for graphing are still called Cartesian coordinates (from Descartes' name: des Cartes). Seeing Descartes as a mathematician explains why he was the kind of philosopher that he was. Now it is hard to reconcile Descartes' status as a scientist and the inspiration he derived from Galileo and others with his clear distrust of experience. Isn't science about experience? We might think so. But the paradox of modern science is its dependence on mathematics. Where does mathematics come from? What makes it true? Many mathematicians will still answer like Plato, but that certainly has little to do with experience. So Descartes belongs to this puzzling, mathematical side of science, not to the side concerned with experience.
 Meditations on First Philosophy is representative of his thought. ‘First philosophy’ simply means what is done first in philosophy. The most important thing about Descartes as a philosopher is that ‘first philosophy’ changed because of what he did. What stood first in philosophy since Aristotle was metaphysics. Thus the first question for philosophy to answer was about what is real. That decided, everything else could be done. With such an arrangement we can say that philosophy function with Ontological Priority. In the Meditations we find that questions about knowledge come to the fore. If there are problems about what we can know, then we may not even be able to know what is real. But if questions about knowledge must be settled first, then this establishes Epistemological Priority for philosophy. Indeed, this leads to the creation of the Theory of Knowledge, Epistemology, as a separate discipline within philosophy for the first time. Previously, knowledge had been treated as falling in the domain of Aristotle's logical works (called, as a whole, the Organon), especially the Posterior Analytics. Modern philosophy has been driven by questions about knowledge. It begins with two principal traditions, Continental Rationalism and British Empiricism. The Rationalists, including Descartes, believed that reason was the fundamental source of knowledge. Empiricist’s believed that experience was emptily epistemologically prioritized and seemingly makes possibly of what has in becoming a very common phenomenon, in that of modern philosophy: Denying that metaphysics are possible at all, or become even that metaphysical questions mean anything. That can happen when epistemology draws the limits of knowledge, or the limits of meaning, so tight that metaphysical statements or questions are no longer allowed.
 The most important issues get raised in the first three of the six Meditations. In the first meditation Descartes begins to consider what he can know. He applies the special method that he has conceived (about which he had already written the Discourse on Method), known as ‘methodical doubt.’ As applied, methodical doubt has two steps: (1) doubt everything that can be doubted, and (2) don't accept anything as known unless it can be established with absolute certainty. Today Descartes is often faulted for requiring certainty of knowledge. But that was no innovation with him: ever since Plato and Aristotle, knowledge was taken to imply certainty. Anything without certainty would just be opinion, not knowledge. The disenchantment with certainty today has occurred just because it turned out to be so difficult to justify certainty to the rigour that Descartes required. Logically the two parts of methodical doubt are very similar, but in the Meditations they are procedurally different. Doubt does its job in the first meditation. Descartes wonders what he can really know about a piece of matter like a lump of wax. He wonders if he might actually be dreaming instead of sitting by the fireplace. Ultimately he wonders if the God he has always believed in might actually be a malevolent Demon capable of using his omnipotence to deceive us even about our own thoughts or our own existence. Thus, there is nothing in all his experience and knowledge that Descartes cannot call into doubt. The junk of history, all the things he ever thought he had known, gets swept away.
 Ever since the Meditations, Descartes' Deceiving Demon has tended to strike people as a funny or absurd idea. Nevertheless, something far deeper and more significant is going on in the first meditation than we might think. It is a problem about the relation of causality to knowledge. The relation of cause to effect had been of interest since Aristotle. There was something odd about it. Given knowledge of a cause (and of the laws of nature), we can usually predict what the effect will be. Touch the hot stove, and you'll get burned. Step off a roof, and you'll fall. But given the effect, it is much more difficult to reason backwards to the cause. The arson squad shows up to investigate the cause of a fire, but that is not an easy task: many things could have caused the fire, and it is always possible that they might not be able to figure out at all what the cause was. The problem is that the relation between cause and effect is not symmetrical. Given a cause, there will be one effect. But given an effect, there could have been many causes able to produce the same effect. And even if we can't predict the effect from the cause.  We can always wait around to see what it is. But if we can't determine the cause from the effect, time forever conceals it from us. This feature of causality made for some uneasiness in mediaeval Western, and even in Indian, philosophy. Many people tried to argue that the effect was contained in the cause, or the cause in the effect. None of that worked, or even made much sense.
 With Descartes, this uneasiness about causality becomes a terror in relation to knowledge: for, in perception, what is the relation of the objects of knowledge to our knowledge of them? Cause to effect. Thus what we possess, our perceptions, are the effects of external causes.  In thinking that we know external objects, we are reasoning backwards from effect to cause. Trouble. Why couldn't our perceptions have been caused by something else? Indeed, in ordinary life we know that they can be. There are hallucinations. Hallucinations can be caused by a lot of things: fever, insanity, sensory deprivation, drugs, trauma, etc. Descartes' Deceiving Demon is more outlandish, but it employs the same principle, and touches the same raw nerve. That raw nerve is now known as the Problem of Knowledge: How can we have knowledge through perception of external objects? There is no consensus on how to solve this even today. The worst thing is not that there haven't been credible solutions proposed.  There have been, but that the solutions should explain why perception is so obvious in ordinary life. Philosophical explanations are usually anything but obvious, however, there is not or anyone sensible person, not even Descartes, really doubts that external objects are there. This is why modern philosophy became so entered on questions about knowledge: it is the Curse of Descartes.
 In the second meditation, Descartes wants to begin building up knowledge from the wreckage of the first meditation. This means starting from nothing. Such an idea of building up knowledge from nothing is called Foundationalism and is one of the mistakes that Descartes makes. Descartes does not and cannot simply start from nothing. Nevertheless, he gets off to a very good start: he decides that he cannot be deceived about his own existence, because if he didn't exist, he wouldn't be around to worry about it. If he didn't exist, he wouldn't be thinking; so if he is thinking, he must exist. This is usually stated in Latin: Cogito ergo sum, ‘I think therefore I am.’ That might be the most famous statement in the history of philosophy, although it does not seem to occur in that form in the Meditations.
 But there is more to it than just Descartes' argument for his own existence. Thinking comes first, and for Descartes that is a real priority. The title of the second meditation actually says, ‘the mind is better known than the body, and the Cogito ergo sum makes Descartes believe, not just that he has proven his existence, but that he has proven his existence as a thinking substance, a mind, leaving the body as some foreign thing to worry about later? That does not really follow, but Descartes clearly thinks that it does and consequently doesn't otherwise provide any special separate proof for the existence of the soul. In the end Descartes will believe that there are two fundamental substances in the world, souls and matter. The essence of soul for him, the attribute that makes a soul what is it, is thinking. The essence of matter for him (given to us in the fifth meditation), the attribute that makes matter what is it, is extension, i.e., that matter takes up space. This is known as Cartesian Dualism that there are two kinds of things. It is something else that people have thought funny or absurd since Descartes. The great difficulty with it was always how souls and their bodies, made of matter, interact or communicate with one another. In Descartes' own physics, forces are transferred by contact; least of mention, the soul, which is unextended and so has no surface, in that might one say is that it is only matter holding to extension, and, cannot contact the body. It holds accountably for reasons from which are to maintain that there is no surface with which to press. The body cannot even hold the soul within it, since the soul has nothing to press upon or carry it along with the body. Problems like this occur whenever the body and soul are regarded as fundamentally different kinds of realities.
 At the present time, it might seem easy to say that the body and soul communicate by passing energy back and forth, of these we might by their unexpressed principle for oscillating requirements deem necessarily for any, and, if not all, for acquiring everyone achievement. Still, might that we behold upon the proximity, for which at any given time can give as a presence upon their aforesaid bearings, because in of each are they that combine of combinations that await to the future. Justly, the presence of real energy in the soul would make it detectable in the laboratory: any kind of energy produces some heat (toward which all energy migrates as it becomes more random, i.e., as energy obeys the laws of the conservation of energy and of entropy), and heat or the radiation it produces (all heat produces electromagnetic radiation) can be detected. But, usually, a theory of the soul wants it to be some kind of thing that cannot be detected in a laboratory--in great measure because souls have not been detected in a laboratory.
 Nevertheless, Descartes' problem is not just confusion or a superstition. Our existence really does seem different from the inside than from the outside. From the inside there is consciousness, experience, colours, music, memories, etc. From the outside there is just the brain: gray goo. How do those two go together? That is the enduring question from Descartes: The Mind-Body Problem. As with the Problem of Knowledge, there is no consensus on a satisfactory answer. To ignore consciousness, as happens in Behaviourism, or to dismiss consciousness as something that is merely a transient state of the material brain, is a kind of reductionism, i.e., to say the one thing is just a state or function of another even though they may seem fundamentally different and there may be no-good reason why we should regard that one thing is more real than of another having less. Much of the talk about the Mind-Body Problem in the 20th century has been reductionistic, starting with Gilbert Ryle's Concept of Mind, which said that ‘mind is to body as kick is to leg.’ A kick certainly doesn't have much reality apart from a leg, but that really doesn't capture the relationship of consciousness to the body or to the brain. When the leg is kicking, we see the leg. But when the brain is ‘minding,’ we don't see the brain, and the body itself is only represented within consciousness. Internally, there is no reason to believe the mind is even in the brain. Aristotle and the Egyptians thought that consciousness was in the heart. In the middle of dreaming or hallucinations, we might not be aware of our bodies at all.
 At the end of the second mediation Descartes may reasonably be said to have proven his own existence, but the existence of the body or of any other external objects is left hanging. If nothing further can be proven, then each of us is threatened with the possibility that I am the only thing that exists. This is called solipsism, from Latin solus, ‘alone’ (sole), and ipse, ‘self.’ Solipsism is not argued, advocated, or even mentioned by Descartes, but it is associated with him because both he and everyone after him have so much trouble proving that something else does exist.
 The third meditation for Descartes' next step was to try in restoring the common sense view as the limit point of knowledge. Even though he is ultimately aiming to show that external objects and the body exist, he is not able to go at that directly. Instead that where for Descartes the attempts to prove the existence of God. This is surprising, since the existence of objects seems much more obvious than the existence of God. All the same, Descartes, methodological work within the spirit of his mathematics, he lead us beyond the gathering the guilt of a conscience frame of mind or any such given to reference. Thereupon, the absence from which are foregathering toward an oftentimes overflowing emptiness he thinks that a pure rational proof of something he can't see is better than no proof of something he can.