LIFE. Descartes was educated at a Jesuit college which was firmly grounded in the scholastic tradition. After furthering his education in Paris, he enlisted in the Dutch and, later, the Bavarian militaries. In 1629 Descartes moved to Holland where he lived in seclusion for 20 years, changing his residence frequently to preserve his privacy. During this period he produced the writings upon which his fame rests. His studies were first restricted to science, and only later did he explore metaphysics. In 1649, Descartes moved to Stockholm at the request of Queen Christina of Sweden who employed him as a philosophy tutor. Christina scheduled the lectures at 5 A.M. The early hours and harsh climate took their toll on Descartes's already weakened condition. He died shortly after in 1650. During his life, Descartes's fame rose to such an extent that many Catholics believed he would be a candidate for sainthood. As his body was transported from Sweden back to France, anxious relic collectors along the path removed pieces of his body. By the time his body reached France, it was considerably reduced in size. Descartes' philosophy developed in the context of the key features of Renaissance and early modern philosophy. Like the humanists, he rejected religious authority in the quest for scientific and philosophical knowledge. For Descartes, reason was both the foundation and guide for pursuing truth. Although Descartes was a devout Catholic, he was also influenced by the Reformation's challenge to Church authority, particularly the challenge against medieval Aristotelianism. He was an active participant in the scientific revolution in both scientific method and in particular discoveries. Finally, and perhaps most importantly, Descartes reacted strongly against the Renaissance resurgence of ancient Greek skepticism. Thus, we find in Descartes' writings a relentless pursuit of absolute certainty.

DISCOURSE ON THE METHOD. Descartes' first discussion of scientific method is in an unfinished work of 1628 titled Rules for the Direction of the Mind. The first 12 of the planned 36 rules deal with the general aspects of his proposed methodology, and are considered early versions of principles which made their way into his later writings. In 1633 Descartes prepared for publication a work on physics called Le Monde which defended a heliocentric view of the universe. That same year the Catholic Church condemned Galileo's Dialogue (1632). Descartes did not think Galileo's views were prejudicial to religion and he worried that his own views might be censured. Thus he suspended publication of it. In 1637 Descartes published a collection of essays titled Optics, Meterology, and Geometry. Prefaced to these essays was a work titled "Discourse on the Method of Rightly Conducting the Reason and Seeking Truth in the Sciences." Most of the "Discourse" was written before the 1633 condemnation of Galileo's Dialogue. However, he later added a concluding section which explained that he insisted on publishing, in spite of political risks. The simple reason was that he counted on the public to help confirm his scientific theories. In the Discourse, Descartes offers a method of inquiry quite different from Bacon's. Whereas Bacon advocated induction, Descartes insists on a more deductive approach.

Most of the Discourse is autobiographical insofar as it traces Descartes intellectual development and how his method assisted him in his investigations. Descartes realized that he needed to reject much of the teachings of his youth. This raised the question as to exactly how he should proceed in replacing old theories with new ones. He found his answer by observing how old parts of cities are replaced with the new. The more elegant cities are those which are methodically built from scratch, not those which continually renovate old sections. Descartes explains that he had learned a variety of methodological approaches in a variety of disciplines. They all had limits, though. Syllogistic logic, he believes, only communicates what we already know. Geometry and algebra are either too abstract in nature for practical application, or too restricted to the shapes of bodies. However, he believed that a more condensed and universal list of methodological rules was better than a lengthy and varied list. The first of these was to accept nothing as true which I did not clearly recognize to be so; that is to say, carefully to avoid precipitation and prejudice in judgments, and to accept in them nothing more than what was presented to my mind so clearly and distinctly that I could have no occasion to doubt it. The second was to divide up each of the difficulties which I examined into as many parts as possible, and as seemed requisite in order that it might be resolved in the best manner possible. The third was to carry on my reflections in due order, commencing with objects that were the most simple and easy to understand, in order to rise little by little, or by degrees, to knowledge of the most complex, assuming an order, even if a fictitious one, among those which do not follow a natural sequence relatively to one another. The last was in all cases to make enumerations so complete and reviews so general that I should be certain of having omitted nothing. Descartes commentator S.V. Keeling argues that Descartes' method, as expressed in the above rules, rests on three mental operations: intuition, deduction, and enumeration. These three abilities constitute our human reason. Intuition involves directly apprehending the simplest components (or "simple natures") of a subject matter. Deduction is not syllogistic, but a process of inferring necessary relations between simple natures. Enumeration is a process of review which we use when deductions become so long that we risk error due to a faulty memory. Descartes realized that he needed a provisional set of moral guidelines to carry him through the transition. He presents four such rules: (1) obey the laws of his country and adhere to his faith in God, (2) to be consistent in following positions, even if they seem doubtful, (3) change his desires rather than the order of the world, (4) to choose the best occupation he could (i.e., that of a philosopher). Accordingly, vowing to live as a spectator rather than an actor, he traveled for a year, then lived in Holland for eight years where he had no relatives and was free from political turmoil. Descartes continues discussing metaphysical issues which he developed more fully in the Meditations. Although Descartes' method had its advocates, it was also criticized by his contemporaries, such as the mathematician Pierre de Fermat, and ultimately dismissed. Leibniz says that Descartes' rules amount to saying "take what you need, and do what you should, and you will get what you want."THE MEDITATIONS. Descartes' most famous and influential philosophical writing is his Meditations. The full title of the work is Meditations on the First Philosophy: In Which the Existence of God and the Distinction Between Mind and Body are Demonstrated. The work was first published in 1641 in Latin and as was translated into French in the following year by the Duc de Luynes. Descartes was so pleased with the French translation that he made some additions and endorsed it for later publication. Descartes passed a manuscript of his Meditations onto his friend, Father Mersenne, who solicited comments from fellow scholars, including Thomas Hobbes. The comments were returned to Descartes. These, along with his lengthy replies -- several times longer than the Meditations themselves -- were included in the second published edition of the Meditations (1642).

DEDICATION. Descartes dedicates the Meditations to the faculty of the Sorbonne, which was the divinity school of the University of Paris. For centuries, the Sorbonne was center of Catholic theology. By dedicating his work to the Sorbonne faculty, Descartes' was announcing that his philosophy was consistent with traditional Catholic theology. Descartes was a devout Catholic and had no desire to offend the Church. Nevertheless, he believed that Aristotelianism had no place in the new scientific age. Cautioned by the fate of Galileo, Descartes proposed his new theories diplomatically. In his Principles of Philosophy, for example, he cautiously suggests a theory of the solar system similar to Galileo's. he expresses his hope that his theory could "be used in Christian teaching without contradicting the text of Aristotle." Descartes announces at the opening that there are two driving issues behind the Meditations: proving the existence of God and the immortality of the soul through natural reason. One would expect divinity school faculty to approve of this plan. However, it is not entirely that these issues are his chief concern in the Meditations. Descartes discusses the importance that the Sorbonne faculty themselves place on rational proofs. Descartes continues by noting how skeptics view the immortality of the soul and the Catholic church's official reaction to such skepticism. Descartes stresses the importance of rationally demonstrating the existence of God and the immortality of the soul. He also notes that he intends to follow the method of investigation proposed in his Discourse on the Method. According to Descartes, geometricians rarely show the falsehood of accepted truths and demonstrations. By contrast, philosophers typically show the falsehood of contentions without venturing to explore truth. Descartes closes the dedication pleading with the faculty of the Sorbonne that their support and influence is necessary for the Meditations to be seen as a successful refutation of skepticism. MEDITATION 1. Descartes opens his Meditations indicating his desire to have only true beliefs. One way to accomplish this is to doubt everything he has learned that might be suspect of error. He does not intend to doubt the truth of every specific idea that comes into his head, but, instead to undermine the foundations of his views. The main assumption he brings under suspicion is the reliability of sensory information. Descartes proposes to systematically follow a process of doubt. The doubt is not a simply common sense one, though, as when I doubt whether black cats are harbingers of bad luck. Instead, his doubting process is philosophical one, and sometimes called "hyperbolic" (or exaggerated) doubt where he proposes to doubt anything which has some reason to doubt. The goal of this doubting process is to arrive at a list of beliefs which are certain and indubitably true. It thus may be viewed as a systematic doubting experiment. The experiment consists of articulating several reasons by which sensory information can be brought into question. When he presents the last of these reasons, there are virtually no items of knowledge he can have confidence in. Much of Descartes argumentation rests on a distinction which, later in the history of philosophy, became known as that between primary and secondary qualities. Briefly, we look at an apple and perceive qualities of redness, sweet smell, roundness, and singularity. Descartes recognized that the qualities of redness and sweet smell do not really belong to the apple. Instead these qualities exist only in the mind of an observer, and are then imposed onto the apple. These have been traditionally called secondary qualities. By contrast, the qualities of roundness and singularity belong to the apple itself, and are not products of the observer's mind. These have been termed primary qualities. For Descartes, secondary qualities arise from what he calls "objects of the senses," and primary qualities from "objects of mathematics."