Descartes, René (1596–1650)

DOI: 10.4324/9780415249126-DA026-1
Version: v1,  Published online: 1998
Retrieved April 21, 2021, from

2. The programme

Descartes’ thought developed and changed over the years. But even so, there are a number of threads that run through it. Like most of his lettered contemporaries, Descartes was educated in a scholastic tradition that attempted to combine Christian doctrine with the philosophy of Aristotle. Indeed, at La Flèche, where he first learned philosophy, Aristotle as interpreted by Aquinas was at the centre of the curriculum. What he learned was an interconnected system of philosophy, including logic, physics, cosmology, metaphysics, morals and theology.

On his own account, Descartes rejected the Aristotelian philosophy as soon as he left school. From the notes Beeckman took on their conversations, it is probable that what dissatisfied him most in what he had been taught was natural philosophy. For an Aristotelian, the understanding of the natural world was grounded in a conception of body as composed of matter and form. Matter was that which remained constant even during the generation and corruption of bodies of different kinds, and that which all bodies of all sorts have in common; form was that which was responsible for the characteristic properties of particular sorts of bodies. For example, form was to explain why earth falls and tends to be cold, and why fire rises and tends to be hot. In contrast, though he came to reject Beeckman’s rather strict atomism, Descartes seems to have been attracted to the kind of mechanistic view of the world that his mentor espoused. Descartes held from then on that the manifest properties of bodies must be explained in terms of the size, shape and motion of the tiny parts that make them up, and rejected the appeal to innate tendencies to behaviour that lay at the foundation of the Aristotelian view (see Aristotle §10).

But even though he rejected much of the philosophy of the schools, there was one element that remained with him: like his teachers at La Flèche, Descartes always held that knowledge has a kind of systematic coherence. In Rule 1 of the Rules Descartes wrote that ‘everything is so interconnected that it is far easier to learn all things together than it is to separate one from the others… All [sciences are] connected with one another and depend upon one another’. Later, when he read Galileo’s Two New Sciences (1638), Descartes dismissed the Italian scientist because his work lacked that kind of coherence (letter to Mersenne, 11 October 1638; Descartes 1984–9 1 vol 3: 124–8). His own project was to build his own interconnected system of knowledge, a system comprising an account of knowledge, a metaphysics, a physics and other sciences. This ambition is summarized in one of his last writings, the Preface to the French edition of the Principles, where he wrote that ‘all philosophy is like a tree, whose roots are metaphysics, whose trunk is physics, and whose branches, which grow from this trunk, are all of the other sciences, which reduce to three principle sciences, namely medicine, mechanics, and morals’. In this way, Descartes saw himself as reconstituting the Aristotelian–Christian synthesis of the scholastics, grounded not in a natural philosophy of matter and form, but in a mechanist conception of body, where everything is to be explained in terms of size, shape and motion.

Certain important features of the Cartesian programme are worth special mention. The Aristotelian–Christian synthesis is founded in a variety of kinds of authority: the authority of the senses, the authority of ancient texts and the authority of his teachers. Descartes wanted to ground his thought in himself alone, and in the reason that God gave him. Since, Descartes claimed, reason gives us genuine certainty, this means that true knowledge is certain. In Rule 3 of the Rules he wrote that ‘concerning things proposed, one ought to seek not what others have thought, nor what we conjecture, but what we can clearly and evidently intuit or deduce with certainty; for in no other way is knowledge acquired’. The rejection of the authority of the senses, texts and teachers shaped Descartes’ thought in fundamental ways. Because of it, his philosophical system began with the Cogito Argument, which establishes the self as the starting-place of knowledge. Moreover, his two most influential works, the Discourse and the Meditations, were written in the first person so as to show the reader how Descartes did or might have come to his own state of knowledge and certainty, rather than telling readers what they are to believe, and thus setting himself up as an authority in his own right. Despite his rejection of authority, however, Descartes always claimed to submit himself to the authority of the Church on doctrinal matters, separating the domain of revealed theology from that of philosophy.

Another important feature of Descartes’ tree of knowledge was its hierarchical organization. Throughout his career he held firmly to the notion that the interconnected body of knowledge that he sought to build has a particular order. Knowledge, for Descartes, begins in metaphysics, and metaphysics begins with the self. From the self we arrive at God, and from God we arrive at the full knowledge of mind and body. This, in turn, grounds the knowledge of physics, in which the general truths of physics (the nature of body as extension, the denial of the vacuum, the laws of nature) ground more particular truths about the physical world. Physics, in turn, grounds the applied sciences of medicine (the science of the human body), mechanics (the science of machines) and morals (the science of the embodied mind).

Citing this article:
Garber, Daniel. The programme. Descartes, René (1596–1650), 1998, doi:10.4324/9780415249126-DA026-1. Routledge Encyclopedia of Philosophy, Taylor and Francis,
Copyright © 1998-2021 Routledge.

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