Where is rene descartes country of origin

His work had a great influence on both mathematicians and philosophers. View seventeen larger pictures. Joachim, the son of the medical doctor Pierre Descartes - , studied law and was a counsellor in the Parliament of Brittany which sat at Rennes.

His mother died in childbirth a year after he was born and the boy, born at the time of her death, also died. Joachim Descartes remarried in to Anne Morin and they had a boy named Joachim born and a girl named Anne born He did not return to live with his father and step-mother, however, but continued living with his grandmother at La Haye. Throughout his childhood, up to his twenties, he was pale and had a persistent cough which was probably due to tuberculosis.

It seems likely that he inherited these health problems from his mother. He entered the college at Easter at the age of eleven years where he became a boarder. He studied there taking courses in classics, logic and traditional Aristotelian philosophy. He also learnt mathematics from the books of Clavius , while studying all the branches of mathematics, namely arithmetic, geometry, astronomy and music. While in the school his health was poor and, instead of rising at 5 a.

In his final years at the school he studied natural philosophy, metaphysics and ethics. School had made Descartes understand how little he knew, the only subject which was satisfactory in his eyes was mathematics.

This idea became the foundation for his way of thinking, and was to form the basis for all his works. Comparatively little is known of Descartes' life between and He spent a while in Paris, apparently keeping very much to himself, and some have speculated that he might have suffered some sort of a breakdown at this time. Then he studied at the University of Poitiers, receiving a law degree from Poitiers in He took the law degree to comply with his father's wishes but he quickly decided that this was not the path he wanted to follow.

He wrote in Discourse on the Method :- I entirely abandoned the study of letters, resolving to seek no knowledge other than that which could be found in myself or else in the great book of the world.

I spent the rest of my youth travelling, visiting courts and armies, mixing with people of diverse temperaments and ranks, gathering various experiences, testing myself in the situations which fortune offered me, and at all times reflecting on whatever came my way so as to derive some profit from it. He may have returned to Paris before he enlisted in the military school at Breda in , becoming a volunteer in the army of Maurice of Nassau. While in Breda his formal study was of military engineering but he started studying mathematics and mechanics under the Dutch scientist Isaac Beeckman, and began to seek a unified science of nature.

Advised by Beeckman, he began considering mechanical problems. While in Holland, he wrote to Beeckman in March about his new ideas:- [ I want to promote a ] completely new science by which all questions in general may be solved that can be proposed about any kind of quantity, continuous as well as discrete. But each according to its own nature. In arithmetic, for instance, some questions can be solved by rational numbers, some by surd numbers, and others can be imagined but not solved.

For continuous quantity I hope to prove that, similarly, certain problems can be solved by using only straight or circular lines, that some problems require other curves for their solution, but still curves which arise from one single motion and which therefore can be traced by the new compasses, which I consider to be no less certain and geometrical than the usual compasses by which circles are traced; and, finally, that other problems can be solved by curved lines generated by separate motions not subordinate to one another.

After this time in Holland he left the service of Maurice of Nassau and travelled through Europe with the plan to join the army of Maximilian of Bavaria. In he joined the Bavarian army and was stationed in Ulm. An important event in his life was three dreams he had in November These he believed were sent by a divine spirit with the intention of revealing to him a new approach to philosophy.

The ideas from these dreams would dominate much of his work from that time on. After this he left the army but since the plague was ravaging in Paris he could not return there but instead began a period of travel. From to Descartes travelled through Europe, spending time in Bohemia , Hungary , Germany, Holland and France - He spent time in in Paris where he made contact with Marin Mersenne , an important contact which kept him in touch with the scientific world for many years, and with Claude Mydorge.

From Paris he travelled through Switzerland to Italy where he spent some time in Venice and in Rome, then he returned to France again He renewed his acquaintance with Mersenne and Mydorge , and met Girard Desargues. His Paris home became a meeting place for philosophers and mathematicians and steadily became more and more busy. By Descartes, tired of the bustle of Paris, the house full of people, and of the life of travelling he had before, decided to settle down where he could work in solitude.

He gave much thought to choosing a country suited to his nature and he chose Holland. What he longed for was somewhere peaceful where he could work away from the distractions of a city such as Paris yet still have access to the facilities of a city.

It was a good decision which he did not seem to regret over the next twenty years. He told Mersenne where he was living so that he might keep in touch with the mathematical world, but otherwise he kept his place of residence a secret. He wrote to Mersenne in October :- [ The foundations of physics ] is the topic which I have studied more than any other and in which, thank God, I have not altogether wasted my time. At least I think that I have found how to prove metaphysical truths in a manner which is more evident than the proofs of geometry - in my opinion, that is: I do not know if I shall be able to convince others of it.

During my first nine months in this country I worked on nothing else. This work was near completion when news that Galileo was condemned to house arrest reached him. He, perhaps wisely, decided not to risk publication and the work was published, only in part, after his death. He explained later his change of direction saying In Holland, Descartes had a number of scientific friends as well as continued contact with Mersenne.

His friendship with Beeckman continued and he also had contact with Mydorge , Hortensius, Huygens and Frans van Schooten the elder. Langer [ ] describes Descartes' life in Holland:- As throughout his life he continued to do his work abed in the mornings.

His evenings he generally devoted to the consideration of his correspondence, which was mainly scientific, rarely personal, and of which he was painstakingly careful, while the intermediate part of the day he gave to relaxation. In matters of money he was neither extravagant nor parsimonious, showing himself in this respect a true philosopher. He always did some entertaining, now more, now less, professing to find considerable enjoyment in conversation, though he was himself rather taciturn.

The work describes what Descartes considers is a more satisfactory means of acquiring knowledge than that presented by Aristotle's logic. Only mathematics, Descartes feels, is certain, so all must be based on mathematics. However his approach through experiment was an important contribution.

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 In [ 22 ] Scott summarises the importance of this work in four points:- He makes the first step towards a theory of invariants, which at later stages derelativises the system of reference and removes arbitrariness. Algebra makes it possible to recognise the typical problems in geometry and to bring together problems which in geometrical dress would not appear to be related at all.

Algebra imports into geometry the most natural principles of division and the most natural hierarchy of method. 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.

Descartes' activities during the early s are not well-documented. He was in France part of the time, visiting Poitou to sell some inherited properties in and visiting Paris.

He went to Italy — Upon his return he lived in Paris, where he was in touch with mathematicians and natural philosophers in the circle of his long-time friend and correspondent Marin Mersenne — While in Paris, he worked on some mathematical problems and derived the sine law of refraction, which facilitated his work on formulating mathematically the shapes of lenses later published in the Dioptrics. His major philosophical effort during these years was on the Rules , a work to convey his new method.

In the Rules , he sought to generalize the methods of mathematics so as to provide a route to clear knowledge of everything that human beings can know. His methodological advice included a suggestion that is familiar to every student of elementary geometry: break your work up into small steps that you can understand completely and about which you have utter certainty, and check your work often.

But he also had advice for the ambitious seeker of truth, concerning where to start and how to work up to greater things. These faculties allow the seeker of knowledge to combine simple truths in order to solve more complex problems, such as the solution to problems in optics , or the discovery of how a magnet works By the end of , Descartes had abandoned work on the Rules , having completed about half of the projected treatise.

In that year he moved to the Dutch Netherlands, and after that he returned to France infrequently, prior to moving to Sweden in Upon arriving in the Netherlands, Descartes undertook work on two sorts of topics. In Summer, , an impressive set of parhelia, or false suns, were observed near Rome. When Descartes heard of them, he set out to find an explanation.

He ultimately hypothesized that a large, solid ice-ring in the sky acts as a lens to form multiple images of the sun []. This work interrupted his investigations on another topic, which had engaged him for his first nine months in the Netherlands —the topic of metaphysics, that is, the theory of the first principles of everything that there is.

The metaphysical objects of investigation included the existence and nature of God and the soul , Subsequently, Descartes mentioned a little metaphysical treatise in Latin—presumably an early version of the Meditations —that he wrote upon first coming to the Netherlands , While working on the parhelia, Descartes conceived the idea for a very ambitious treatise.

This work eventually became The World , which was to have had three parts: on light a general treatise on visible, or material, nature , on man a treatise of physiology , and on the soul. Only the first two survive and perhaps only they were ever written , as the Treatise on Light and Treatise on Man.

In these works, which Descartes decided to suppress upon learning of the condemnation of Galileo , , he offered a comprehensive vision of the universe as constituted from a bare form of matter having only length, breadth, and depth three-dimensional volume and carved up into particles with size and shape, which may be in motion or at rest, and which interact through laws of motion enforced by God —4.

These works contained a description of the visible universe as a single physical system in which all its operations, from the formation of planets and the transmission of light from the sun, to the physiological processes of human and nonhuman animal bodies, can be explained through the mechanism of matter arranged into shapes and structures and moving according to three laws of motion. In fact, his explanations in the World and the subsequent Principles made little use of the three laws of motion in other than a qualitative manner.

After suppressing his World , Descartes decided to put forward, anonymously, a limited sample of his new philosophy, in the Discourse with its attached essays. The Discourse recounted Descartes' own life journey, explaining how he had come to the position of doubting his previous knowledge and seeking to begin afresh.

It offered some initial results of his metaphysical investigations, including mind—body dualism. It did not, however, engage in the deep skepticism of the later Meditations , nor did it claim to establish, metaphysically, that the essence of matter is extension. This last conclusion was presented merely as a hypothesis whose fruitfulness could be tested and proven by way of its results, as contained in the attached essays on Dioptrics and Meteorology.

In his Meteorology , Descartes described his general hypothesis about the nature of matter, before continuing on to provide accounts of vapors, salt, winds, clouds, snow, rain, hail, lightning, the rainbow, coronas, and parhelia. He presented a corpuscularian basis for his physics, which denied the atoms-and-void theory of ancient atomism and affirmed that all bodies are composed from one type of matter, which is infinitely divisible In the World , he had presented his non-atomistic corpuscularism, but without denying void space outright and without affirming infinite divisibility — Indeed, Descartes claimed that he could explain these qualities themselves through matter in motion , a claim that he repeated in the Meteorology —6.

Unlike Descartes' purely extended matter, which can exist on its own having only size and shape, many scholastic Aristotelians held that prime matter cannot exist on its own.

The four Aristotelian elements, earth, air, fire, and water, had substantial forms that combined the basic qualities of hot, cold, wet, and dry: earth is cold and dry; air is hot and wet; fire is hot and dry; and water is cold and wet. For earth, that activity is to approach the center to the universe; water has the same tendency, but not as strongly. For this reason, Aristotelians explained, the planet earth has formed at the center, with water on its surface.

This form then organizes that matter into the shape of a rabbit, including organizing and directing the activity of its various organs and physiological processes. Although in the World and Meteorology Descartes avoided outright denial of substantial forms and real qualities, it is clear that he intended to deny them ; ; , , Two considerations help explain his tentative language: first, when he wrote these works, he was not yet prepared to release his metaphysics, which would support his hypothesis about matter and so rule out substantial forms ; and, second, he was sensitive to the prudential value of not directly attacking the scholastic Aristotelian position , since it was the accepted position in university education and was strongly supported by orthodox theologians, both Catholic and Protestant —6; Descartes' correspondence from the second half of the s repays close study, among other things for his discussions of hypothesis-confirmation in science, his replies to objections concerning his metaphysics, and his explanation that he had left the most radical skeptical arguments out of this work, since it was written in French for a wide audience , In , Descartes fathered a daughter named Francine.

Her mother was Descartes' housekeeper, Helena Jans. They lived with Descartes part of the time in the latter s, and Descartes was arranging for them to join him when he learned of Francine's untimely death in September Descartes subsequently contributed a dowry for Helena's marriage in Watson , This was the Meditations , and presumably he was revising or recasting the Latin treatise from In the end, he and Mersenne collected seven sets of objections to the Meditations , which Descartes published with the work, along with his replies , Some objections were from unnamed theologians, passed on by Mersenne; one set came from the Dutch priest Johannes Caterus; one set was from the Jesuit philosopher Pierre Bourdin; others were from Mersenne himself, from the philosophers Pierre Gassendi and Thomas Hobbes, and from the Catholic philosopher-theologian Antoine Arnauld.

As previously mentioned, Descartes considered the Meditations to contain the principles of his physics. Descartes and his followers included topics concerning the nature of the mind and mind—body interaction within physics or natural philosophy, on which, see Hatfield Once Descartes had presented his metaphysics, he felt free to proceed with the publication of his entire physics.

However, he needed first to teach it to speak Latin , the lingua franca of the seventeenth century. He hatched a scheme to publish a Latin version of his physics the Principles together with a scholastic Aristotelian work on physics, so that the comparative advantages would be manifest. For this purpose, he chose the Summa philosophiae of Eustace of St. That part of his plan never came to fruition. Ultimately, his physics was taught in the Netherlands, France, England, and parts of Germany.

For the Catholic lands, the teaching of his philosophy was dampened when his works were placed on the Index of Prohibited Books in , although his followers in France, such as Jacques Rohault —72 and Pierre Regis — , continued to promote Descartes' natural philosophy.

The Principles appeared in Latin in , with a French translation following in In the letter he explained important elements of his attitude toward philosophy, including the view that in matters philosophical one must reason through the arguments and evaluate them for one's self 9B He also presented an image of the relations among the various parts of philosophy, in the form of a tree:. The extant Principles offer metaphysics in Part I; the general principles of physics, in the form of his matter theory and laws of motion, are presented in Part II, as following from the metaphysics; Part III concerns astronomical phenomena; and Part IV covers the formation of the earth and seeks to explain the properties of minerals, metals, magnets, fire, and the like, to which are appended discussions of how the senses operate and a final discussion of methodological issues in natural philosophy.

His intent had been also to explain in depth the origins of plants and animals, human physiology, mind—body union and interaction, and the function of the senses. In the end, he had to abandon the discussion of plants and animals Princ.

From early in his correspondence with Mersenne, Descartes showed a concern to avoid becoming embroiled in theological controversy or earning the enmity of church authorities —6, , Nonetheless, he was drawn into theological controversy with Calvinist theologians in the Netherlands.

In the latter s, Henry le Roy — , or Regius, a professor of medicine in Utrecht, taught Descartes' system of natural philosophy. Already by , Gisbert Voetius — , a theologian at Utrecht, expressed his displeasure over this to Mersenne Controversy brewed, at first between Regius and Voetius, with Descartes advising the former. Voetius, who was rector of the University, convinced the faculty senate to condemn Descartes' philosophy in He and his colleagues published two works in and attacking Descartes' philosophy, to which Descartes himself responded by publishing a Letter to Voetius The controversy simmered through the mids.

Descartes eventually had a falling out with Regius, who published a broadsheet or manifesto that deviated from Descartes' theory of the human mind. Descartes replied with his Comments on a Certain Broadsheet In the mids, Descartes continued work on his physiological system, which he had pursued throughout the s.

He allowed his Treatise on Man to be copied —7 and he began a new work , Description of the Human Body , in which he sought to explain the embryonic development of animal bodies. During this period he corresponded with Princess Elisabeth, at first on topics in metaphysics stemming from her reading of the Meditations and then on the passions and emotions.

Eventually, he wrote the Passions of the Soul , which gave the most extensive account of his behavioral physiology to be published in his lifetime and which contained a comprehensive and original theory of the passions and emotions. Portions of this work constitute what we have of Descartes' moral theory. In , Descartes accepted the invitation of Queen Christina of Sweden to join her court.

On the day he delivered them to her, he became ill. He never recovered. He died on 11 February In general, it is rare for a philosopher's positions and arguments to remain the same across an entire life.

This means that, in reading philosophers' works and reconstructing their arguments, one must pay attention to the place of each work in the philosophical development of the author in question. Readers of the philosophical works of Immanuel Kant are aware of the basic distinction between his critical and precritical periods.

Readers of the works of G. Leibniz are also aware of his philosophical development, although in his case there is less agreement on how to place his writings into a developmental scheme. Scholars have proposed various schemes for dividing Descartes' life into periods. In effect, he adopted a hypothetico-deductive scheme of confirmation, but with this difference: the range of hypotheses was limited by his metaphysical conclusions concerning the essence of mind and matter, their union, and the role of God in creating and conserving the universe.

Argumentative differences among the World , Discourse , and Meditations and Principles may then be seen as arising from the fact that in the s Descartes had not yet presented his metaphysics and so adopted an empirical mode of justification, whereas after he could appeal to his published metaphysics in seeking to secure the general framework of his physics.

Other scholars see things differently. John Schuster finds that the epistemology of the Rules lasted into the s and was superseded unhappily, in his view only by the metaphysical quest for certainty of the Meditations.

Daniel Garber , 48 also holds that Descartes abandoned his early method after the Discourse. Machamer and McGuire believe that Descartes expected natural philosophy to meet the standard of absolute certainty through the time of the Meditations , and that he in effect admitted defeat on that score in the final articles of the Principles , adopting a lower standard of certainty for his particular hypotheses such as the explanation of magnetism by corkscrew-shaped particles.

These contrasting views of Descartes' intellectual development suggest different relations between his metaphysics and physics. Schuster treats Descartes' metaphysical arguments as a kind of afterthought. There are also differences among interpreters concerning the relative priority in Descartes' philosophical endeavors of epistemology or the theory of knowledge as opposed to metaphysics or first philosophy.

In the account of Descartes' development from Sec. Thereafter, his aim was to establish a new natural philosophy based on a new metaphysics. In the extant works from the s, the World and Discourse plus essays, he argued for the general principles of his physics, including his conception of matter, on empirical grounds. He argued from explanatory scope and theoretical parsimony. As regards parsimony or simplicity, he pointed out that his reconceived matter had only a few basic properties especially size, shape, position, and motion , from which he would construct his explanations.

He claimed great explanatory scope by contending that his explanations could extend to all natural phenomena, celestial and terrestrial, inorganic and organic. But throughout the s, Descartes claimed that he also was in possession of a metaphysics that could justify the first principles of his physics, which he finally presented in the Meditations and Principles. Some scholars emphasize the epistemological aspects of Descartes' work, starting with the Rules and continuing through to the Principles.

Accordingly, the main change in Descartes' intellectual development is the introduction of skeptical arguments in the Discourse and Meditations. Many interpreters, represented prominently in the latter twentieth century by Richard Popkin , believe that Descartes took the skeptical threat to knowledge quite seriously and sought to overcome it in the Meditations.

By contrast, in the main interpretive thread followed here, skeptical arguments were a cognitive tool that Descartes used in order to guide the reader of the Meditations into the right cognitive frame of mind for grasping the first truths of metaphysics. Achieving stable knowledge of such truths would have as a side-effect security against skeptical challenge.

The reader who is curious about these issues should read the relevant works of Descartes, together with his correspondence from the latter half of the s and early s. Descartes first presented his metaphysics in the Meditations and then reformulated it in textbook-format in the Principles.

His metaphysics sought to answer these philosophical questions: How does the human mind acquire knowledge? What is the mark of truth? What is the actual nature of reality? How are our experiences related to our bodies and brains? Is there a benevolent God, and if so, how can we reconcile his existence with the facts of illness, error, and immoral actions?

Descartes had no doubt that human beings know some things and are capable of discovering others, including at least since his metaphysical insights of fundamental truths about the basic structure of reality. Yet he also believed that the philosophical methods taught in the schools of his time and used by most of his contemporaries were deeply flawed. He believed that the doctrines of scholastic Aristotelian philosophy contained a basic error about the manner in which fundamental truths, such as the truths of metaphysics, are to be gained.

He then went on to challenge the veridicality of the senses with the skeptical arguments of First Meditation, including arguments from previous errors, the dream argument, and the argument from a deceptive God or an evil deceiver. Descartes explained these convictions as the results of childhood prejudice , 17, 69, ; Princ. As children, we are naturally led by our senses in seeking benefits and avoiding bodily harms.

Descartes denied that the senses reveal the natures of substances. He held that in fact the human intellect is able to perceive the nature of reality through a purely intellectual perception. Descartes constructed the Meditations so as to secure this process of withdrawal from the senses in Meditation I. Hence, he sets up clear and distinct intellectual perception, independent of the senses, as the mark of truth , 62, We consider these results in Secs.

For now, let us examine what Descartes thought about the senses as a source of knowledge that was different from the pure intellect. In the Meditations , he held that the essence of matter could be apprehended by innate ideas, independently of any sensory image —5, 72—3. To that extent, his later position agrees with the Platonic tradition in philosophy, which denigrated sensory knowledge and held that the things known by the intellect have a higher reality than the objects of the senses.

Descartes, however, was no Platonist, a point to which we will return. His attitude toward the senses in his mature period was not one of total disparagement.

Descartes assigned two roles to the senses in the acquisition of human knowledge. First, he acknowledged that the senses are usually adequate for detecting benefits and harms for the body. In this connection, he was agreeing with the conception of the function of the senses that was widely shared in the traditional literature in natural philosophy, including the Aristotelian literature, as well as in the medical literature on the natural functions of the senses.

Second, he recognized that the senses have an essential role to play in natural philosophy. The older interpretive literature sometimes had Descartes claiming that he could derive all natural philosophical or scientific knowledge from the pure intellect, independent of the senses. But Descartes knew full well that he could not do that.

He distinguished between the general principles of his physics and the more particular mechanisms that he posited to explain natural phenomena, such as magnetism or the properties of oil and water. These include the fundamental doctrine that the essence of matter is extension Princ. As to particular phenomena, in general he had to rely on observations to determine their properties such as the properties of the magnet , and he acknowledged that multiple hypotheses about subvisible mechanisms could be constructed to account for those phenomena.

The natural philosopher must, therefore, test the various hypotheses by their consequences, and consider empirical virtues such as simplicity and scope Disc. VI; Princ. Further, Descartes knew that some problems rely on measurements that can only be made with the senses, including determining the size of the sun or the refractive indexes of various materials Met. Although Descartes recognized an important role for the senses in natural philosophy, he also limited the role of sense-based knowledge by comparison with Aristotelian epistemology.

According to many scholastic Aristotelians, all intellectual content arises through a process of intellectual abstraction that starts from sensory images as present in the faculty of imagination. Mathematical objects are formed by abstraction from such images. Even metaphysics rests on knowledge derived by abstraction from images. Of course, in this Aristotelian scheme the intellect plays an important role in grasping mathematical objects or the essences of natural things through considering images.

By contrast, Descartes affirmed that the truths of mathematics and metaphysics are grasped by the intellect operating independently of the senses and without need for assistance from the faculty of imagination. In Descartes' scheme of mental capacities, knowledge does not arise from the intellect alone. The intellect may present some content as true, but by itself it does not affirm or deny that truth.

That function belongs to the will. A judgment, and hence an instance of at least putative knowledge, does not arise in this scheme until the will has affirmed or denied the content presented by the intellect. IV, Princ. The intellect is the power of perception or representation. Acts of pure intellect occur without the need for any accompanying brain processes; these are purely intellectual perceptions.

But there are other intellectual acts that require the presence of the body: sense perception, imagination, and corporeal body-involving memory. These intellectual acts are less clear and distinct than acts of pure intellect, and may indeed be obscure and confused as in the case of color sensations. Nonetheless, the will may affirm or deny such content.

As discussed in the next subsection, error can arise in these judgments. In sum, in considering Descartes' answer to how we know, we can distinguish classes of knowledge that differ as regards the degree of certainty one may expect to achieve. Metaphysical first principles as known by the intellect acting alone should attain absolute certainty.

Practical knowledge concerning immediate benefits and harms is known by the senses. Such knowledge is usually good enough. Objects of natural science are known by a combination of pure intellect and sensory observation: the pure intellect tells us what properties bodies can have, and we use the senses to determine which particular instances of those properties bodies do have.

For submicroscopic particles, we must reason from observed effects to potential cause. In these latter cases, our measurements and our inferences may be subject to error, but we may also hope to arrive at the truth. Clarity and distinctness of intellectual perception is the mark of truth. In the fifth set of Objections to the Meditations , Gassendi suggests that there is difficulty concerning. Gassendi has in effect asked how it is that we should recognize clear and distinct perceptions.

If clarity and distinctness is the mark of truth, what is the method for recognizing clarity and distinctness? In reply, Descartes claims that he has already supplied such a method What could he have in mind? It cannot be the simple belief that one has attained clarity and distinctness, for Descartes himself acknowledges that individuals can be wrong in that belief , Nonetheless, he does offer a criterion.

We have a clear and distinct perception of something if, when we consider it, we cannot doubt it That is, in the face of genuine clear and distinct perception, our affirmation of it is so firm that it cannot be shaken, even by a concerted effort to call the things thus affirmed into doubt. As mentioned in 3. The intellect perceives or represents the content of the judgment; the will affirms or denies that content. The inclination of the will is so strong that it amounts to compulsion; we cannot help but so affirm.

Descartes thus makes unshakable conviction the criterion. Can't someone be unshakable in their conviction merely because they are stubborn? Assuredly so. But Descartes is talking about a conviction that remains unshakable in face of serious and well-thought out challenges To be immune from doubt does not mean simply that you do not doubt a proposition, or even that it resists a momentary attempt to doubt; the real criterion for truth is that the content of a proposition is so clearly perceived that the will is drawn to it in such a way that the will's affirmation cannot be shaken even by the systematic and sustained doubts of the Meditations.

Perhaps because the process for achieving knowledge of fundamental truths requires sustained, systematic doubt, Descartes indicates that such doubt should be undertaken only once in the course of a life ; Even so, problems remain. Having extracted clarity and distinctness as the criterion of truth at the beginning of the Third Meditation, Descartes immediately calls it into question. In the course of the Third Meditation, Descartes constructs an argument for the existence of God that starts from the fact that he has an idea of an infinite being.

The argument is intricate. Descartes then applies that principle not to the mere existence of the idea of God as a state of mind, but to the content of that idea. Descartes characterizes that content as infinite, and he then argues that a content that represents infinity requires an infinite being as its cause. He concludes, therefore, that an infinite being, or God, must exist. He then equates an infinite being with a perfect being and asks whether a perfect being could be a deceiver.

The second and fourth sets of objections drew attention to a problematic characteristic of this argument.

In the words of Arnauld:. Arnauld here raises the well-known problem of the Cartesian circle, which has been much discussed by commentators in recent years. In reply to Arnauld, Descartes claims that he avoided this problem by distinguishing between present clear and distinct perceptions and those that are merely remembered He is not here challenging the reliability of memory Frankfurt Rather, his strategy is to suggest that the hypothesis of a deceiving God can only present itself when we are not clearly and distinctly perceiving the infinity and perfection of God, because when we are doing that we cannot help but believe that God is no deceiver.

It is as if this very evident perception is then to be balanced with the uncertain opinion that God might be a deceiver The evident perception wins out and the doubt is removed. Descartes explicitly responds to the charge of circularity in the manner just described. Over the years, scholars have debated whether this response is adequate. Some scholars have constructed other responses on Descartes' behalf or have found such responses embedded in his text at various locations.

One type of response appeals to a distinction between the natural light and clear and distinct perception, and seeks to vindicate the natural light without appeal to God Jacquette Another response suggests that, in the end, Descartes was not aiming at metaphysical certainty concerning a mind-independent world but was merely seeking an internally coherent set of beliefs Frankfurt A related response suggests that Descartes was after mere psychological certainty Loeb The interested reader can follow up this question by turning to the literature here cited as also Carriero , Doney , and Hatfield Building on his claim that clear and distinct perceptions are true, Descartes seeks to establish various results concerning the nature of reality, including the existence of a perfect God as well as the natures of mind and matter to which we turn in the next subsection.

Here we must ask: What is the human mind that it can perceive the nature of reality? Descartes has a specific answer to this question: the human mind comes supplied with innate ideas that allow it to perceive the main properties of God infinity and perfection , the essence of matter, and the essence of mind.

Descartes rejected both alternatives. He denied, along with many of his contemporaries, that there are eternal truths independent of the existence of God. But he also denied that the eternal truths are fixed in God's intellect.

Some Neoplatonist philosophers held that the eternal truths in the human mind are copies, or ectypes, of the archetypes in the mind of God. Eternal truths are latent in God's creative power, and he understands this, so that if human beings understand the eternal truths as eternal, they also do so by understanding the creative power of God Hatfield Descartes had a different account.

He held that the eternal truths are the free creations of God , , ; , , originating from him in a way that does not distinguish among his power, will, and intellect.

He might have created other essences, although we are unable to conceive what they might have been. Our conceptual capacity is limited to the innate ideas that God has implanted in us, and these reflect the actual truths that he created.

God creates the eternal truths concerning logic, mathematics, the nature of the good, the essences of mind and matter , and he creates the human mind and provisions it with innate ideas that correspond to those truths. However, even in this scheme there must remain some eternal truths that are not created by God: those that pertain to the essence of God himself, including his existence and perfection see Wells Descartes reveals his ontology implicitly in the Meditations , more formally in the Replies, and in textbook fashion in the Principles.

The main metaphysical results that describe the nature of reality assert the existence of three substances, each characterized by an essence. The first and primary substance is God, whose essence is perfection. In fact, God is the only true substance, that is, the only being that is capable of existing on its own. Descartes' arguments to establish the essences of these substances appeal directly to his clear and distinct perception of those essences.

The essence of matter is extension in length, breadth, and depth. Cartesian matter does not fill a distinct spatial container; rather, spatial extension is constituted by extended matter there is no void, or unfilled space. Modes are properties that exist only as modifications of the essential principal and the general attributes of a substance.

In addition to its essence, extension, matter also has the general attributes of existence and duration. The individual parts of matter have durations as particular modes. All the modes of matter, including size, shape, position, and motion, can exist only as modifications of extended substance.

The essence of mind is thought. Besides existence and duration, minds have the two chief powers or faculties previously mentioned: intellect and will. The intellectual or perceiving power is further divided into the modes of pure intellect, imagination, and sense perception. Pure intellect operates independently of the brain or body; imagination and sense perception depend upon the body for their operation as does corporeal memory.

The will is also divided into various modes, including desire, aversion, assertion, denial, and doubt. These always require some intellectual content whether pure, imagined, or sensory upon which to operate.

It seems he held that the mind essentially has a will, but that the intellectual or perceptive, or representational power is more basic, because the will depends on it in its operation. What role does consciousness play in Descartes' theory of mind?

Many scholars believe that, for Descartes, consciousness is the defining property of mind e. There is some support for this position in the Second Replies. If mind is thinking substance and thoughts are essentially conscious, perhaps consciousness is the essence of thought? Descartes in fact did hold that all thoughts are, in some way, conscious He did not mean by this that we have reflective awareness of, and can remember, every thought that we have In the Second Meditation, he describes himself as a thinking thing by enumerating all the modes of thoughts of which he is conscious: understanding or intellection , willing, imagining, and at this point, at least seeming to have sense perceptions He thus sets up consciousness as a mark of thought.

But is it the essence? There is another possibility. If perception intellection, representation is the essence of thought, then all thoughts might be conscious in a basic way because the character of the intellectual substance is to represent, and any representation present in an intellectual substance is thereby conscious.

Similarly, any act of will present in an intellectual substance also is available to consciousness, because it is of the essence of such a substance to perceive its own states Accordingly, perception or representation is the essence of mind, and consciousness follows as a result of the mind's being a representing substance.

All the same, in distinguishing between thoughts possessed of consciousness and thoughts of which we are reflectively aware, Descartes opened a space for conscious thoughts that we don't notice or remember.

As in his theory of the senses Sec. Descartes was born on March 31, , in La Haye en Touraine, a small town in central France, which has since been renamed after him to honor its most famous son. He was the youngest of three children, and his mother, Jeanne Brochard, died within his first year of life. His father, Joachim, a council member in the provincial parliament, sent the children to live with their maternal grandmother, where they remained even after he remarried a few years later.

So did spending the next four years earning a baccalaureate in law at the University of Poitiers. Some scholars speculate that he may have had a nervous breakdown during this time. Descartes later added theology and medicine to his studies. So he traveled, joined the army for a brief time, saw some battles and was introduced to Dutch scientist and philosopher Isaac Beeckman, who would become for Descartes a very influential teacher.

A year after graduating from Poitiers, Descartes credited a series of three very powerful dreams or visions with determining the course of his study for the rest of his life. Descartes is considered by many to be the father of modern philosophy, because his ideas departed widely from current understanding in the early 17th century, which was more feeling-based. Since Descartes believed that all truths were ultimately linked, he sought to uncover the meaning of the natural world with a rational approach, through science and mathematics—in some ways an extension of the approach Sir Francis Bacon had asserted in England a few decades prior.

In addition to Discourse on the Method , Descartes also published Meditations on First Philosophy and Principles of Philosophy , among other treatises.

Although philosophy is largely where the 20th century deposited Descartes—each century has focused on different aspects of his work—his investigations in theoretical physics led many scholars to consider him a mathematician first.