Cartesian naturalism: natural science in the <i>Meditations</i>

In a letter to the translator accompanying the French translation of the Principles of Philosophy, Descartes presents a clearly foundationalist view of learning. In this perspective, the ultimate basis of all learning is metaphysics (the first philosophy); it supports physics, and physics supports all other sciences. Moreover, Descartes asserts that there must be indubitable principles and that all the other true propositions must be derived from them. However, in his major work on metaphysics, the Meditations, he not only describes some natural-scientific views that are discussed in his posthumous natural-scientific works—The World and the Treatise on Man—as elements of important arguments but also makes multiple crucial arguments that he claims to be ‘clear by the natural light’, which are not necessarily deduced from a small number of principles. In this sense, his first philosophy is ‘naturalistic’, in Quine’s sense of the term, and nonfoundationalist. In this article, I investigate the use of the phrase ‘natural light’, consider some views that are not necessarily ‘clear and distinct’ but serve as important reasons for methodical doubt, and enumerate the natural-scientific views that Descartes uses in the Meditations, thus clarifying the true characteristics of his first philosophy.