Descartes, René

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DESCARTES, RENÉ

DESCARTES, RENÉ (1596–1650), French philosopher. Descartes is held to be the father of modern philosophy and chief architect of the modern approach to the relationship between science and religion. The scholastic tradition, already ably criticized by Descartes's time, was in effect obviated by a new, universal metaphysical construction based on the conceptual apparatus of Descartes. The entire development of European philosophy, in all its diverse tendencies, has been dependent, directly or indirectly, on the Cartesian legacy. If it is true, as Whitehead said, that European philosophy consists of footnotes to Plato, modern European philosophy, in the same sense, consists of footnotes to Descartes.

Born to a noble Roman Catholic family, Descartes was educated in the physics and metaphysics of an Aristotelian and Thomist tradition, and in medicine and law. He joined the Dutch army, and, while in the Netherlands, became interested in mathematics and the new physics. Having traveled in various countries, he returned to France, where he outlined the first version of a new method of thinking based on mathematics (Rules for the Direction of the Mind), but he did not complete or publish it. After settling in the Netherlands, he maintained contact with scholars by letter; Marin Mersenne was his main correspondent. He passed the last year of his life in Sweden at the court of Queen Christina.

Descartes's aim was to use mathematics as a model for developing a fully unified form of human knowledge. He applied this method in his Treatise on the World. The trial of Galileo and condemnation of Galileo's Dialogues convinced Descartes not to print his own work, which clearly confirmed the heliocentric theory. In 1637 he published several parts of it with a methodological introduction, called The Discourse on Method, which was to become one of the greatest texts of modern thought. In 1641 he published his other major work, Meditations on First Philosophy, which had previously been sent to a number of scholars, among them Gassendi, Hobbes, and Arnauld; their objections and Descartes's replies were subsequently published with the main text. The Principles of Philosophy appeared in 1644 and The Passions of the Soul in 1649. Some other works and his voluminous correspondence were published posthumously.

The Discourse indicates that for Descartes philosophy was a methodological and conceptual basis for the sciences, to make them useful in the domination of nature. Although the metaphysical problems he discussed in his Meditations are not subordinated to this goal, it is clear that Descartes was interested only in matters that could be solved by rational means and that his mental attitude was essentially antihistorical.

Cartesian method demands that we accept as true only what is presented "clearly and distinctly" to our mind, leaving no room for doubt. We should suspend our judgment in all matters where the slightest doubt is possible, including all the truths of common sense, in order to find something that resists all doubts. Sense-perception does not provide us with any indubitable knowledge, since we cannot be a priori certain that we are not dreaming or that we are not being deceived by a malicious demon. But my very act of doubting, however far extended, and therefore the fact that I am thinking, cannot itself be doubted. And thus I find at least this one certainty in which I cannot be deceived: I think, and I, the thinker, must exist; no demon could induce me to err on this point. This reasoning, summarized in the famous formula "Cogito ergo sum," can be admitted as the basis of knowledge.

The cogito, accepted as a kind of epistemological absolute, is in Descartes's work an implicit challenge to the authority of tradition and an appeal to look for truth only in the reason of a thinking individual. And it implies that the only object that is directly and indubitably accessible to one's mind is its own activity; wherever else we start, our beliefs will be exposed to doubt.

While I grasp my existence as identical with the awareness of existence, I observe, according to Descartes, that nothing belongs necessarily to my nature except the fact that I think; therefore I may describe myself as a thinking thing, or thinking substance, or immaterial soul. This transition from "I think" to "I am a thinking substance" was strongly criticized by Descartes's contemporaries and later. It gave rise to the question, much debated in the twentieth century, whether or not the "self" or "I" can be described at all in "objective" categories.

Our mind, according to Descartes, has a natural light whereby it is capable of acquiring knowledge on most important issues without relying on sense-perception. We have in our mind a natural idea of God, or a perfect being. Since our mind clearly perceives that it is not perfect itself (of which the fact of doubting is evidence, if indeed evidence is needed), it could not have fabricated this idea, as a more perfect thing cannot be produced by a less perfect; consequently the very presence of this idea is a proof of the actual existence of the perfect being. This psychological argument for God's existence, like the ontological argument in traditional version, which Descartes accepts as well, implies nothing about God's presence and signs in the world. God's first function, in Descartes's construction, is to assure the reliability of human knowledge: being perfect, God cannot deceive us, therefore we can rely both on our commonsense belief in the reality of the material world and on our intellectual intuition. (Many critics pointed out the circularity in this reasoning: acts of intuition are necessary to acquire the certainty of the existence of God, who subsequently appears as a guarantor of the infallibility of those very acts.) We can thus affirm the reality of the material world.

Descartes conceived the material world, or "extension," in strictly mechanistic terms. All processes are explained by the laws of mechanics; living organisms behave according to the same principles that govern artificial automata; there is no specific realm of life. To be sure, human beings are endowed with an immaterial soul, which is the seat of all sensations; animals, having no soul, are no more than mechanisms, and their reactions are just mechanical movements. In human beings, organic (that is, mechanical) processes, should be distinguished from psychological events in the soul. The human organism does not differ from other mechanisms; its death is a physical phenomenon, whereas the separation of the soul is not the cause but the effect of death. The two substances—soul and body—that make up the human being cannot affect each other; therefore the question of how we can realize, in perception, the mechanical impacts of other things on our bodies and cause movements of our body by the sheer act of will becomes difficult to solve; and Descartes's followers, when trying to explain the unity of soul and body and their mutual influence, naturally tended to materialist or occasionalist explanations, none of which conformed to the master's doctrine, which implied both that the soul is absolutely free and capable of dominating the affects, and that the affects are passive states caused by the movement of blood.

Descartes's philosophy almost instantaneously produced new lines of division in European intellectual life. Though attacked, mainly for its rationalist rigor, by both Protestants (the school of Voetius) and Catholics (all Descartes's works were put on the Index of Prohibited Books in 1663), its impact was soon to be felt not only among philosophers, scientists, and physicians, but among theologians as well. In the Netherlands, Coccejus's school tried to apply Descartes's methods in theological investigations; in France, Malebranche and other occasionalists attempted a Catholic assimilation of a somewhat modified Cartesianism. In the Jansenist milieu the influence of Descartes was very strong. By the end of the seventeenth century few orthodox Cartesians remained, but the impact of the doctrine was felt throughout the early French Enlightenment; its general rationalist and determinist approach laid the foundation of eighteenth-century materialism, while its skeptical side and the cogito were crucially important in the rise of modern idealism, starting with Berkeley.

Although there are no reasons to doubt that Descartes himself believed in God and in the immortality of the soul, his philosophy made God absent in the world and thus useless in interpreting it. Descartes was not, strictly speaking, a deist, insofar as, according to him, the force needed to sustain the universe in existence is the same as that needed to create it; yet he contributed decisively to the deist and atheist movements of the subsequent centuries. He was the modern founder of totally secularized thinking. Outstanding twentieth-century Thomists (Gilson, Maritain) saw in Descartes the main author of what they believed to be the aberration of modern intellectual life, of its individualist, idealist, and rationalist tendencies. And the problem of the transition from the cogito to the world and vice versa has remained, thanks to Descartes, one of the crucial issues in modern phenomenology and existential philosophy.

Bibliography

Works by Descartes

Correspondance. 8 vols. Edited by Charles Adam and Gérard Milhaud. Paris, 1936–1963.

Descartes: Philosophical Writings. Selected, translated, and edited by Elizabeth Anscombe and P. T. Geach. Edinburgh, 1964. Contains a good bibliography.

Œuvres de Descartes. 2d ed. 12 vols. Edited by Charles Adam and Paul Tannery. Paris, 1956–1957.

Philosophical Letters. Translated and edited by Anthony Kenny. Oxford, 1970.