Abstract

What are Descartes's criteria for substance, and how many material objects meet them? A passage in the Synopsis of the Meditations has led some to portray him as a monist about extended substance and others to say that he does not even use “extended substance” as a count term. After considering Descartes's two criteria for substance, as well as his account of transubstantiation, we see that these answers are mistaken. Descartes countenances an infinity of extended substances. These are quantities of matter that can survive any rearrangement or scattering of their parts, but not the annihilation of any of them.