Abstract
ONTOLOGY, as a special field of philosophical inquiry, has been considerably neglected in modern times, and it is thus not surprising that little attention has been paid to Descartes in respect of ontology, especially since he himself did not bring it into prominence in his writings. His not having done so is quite in line with his characteristic procedure, which was not to engage head-on the fundamental positions or presuppositions which he was disputing, but rather to distract attention from them so as to secure an unantagonistic hearing for his own theories. I shall argue that Descartes had an ontology, which was not merely implicit, and that when we discern his ontology we can see his position in the basic areas—metaphysics, epistemology and methodology, philosophical psychology or theory of mind-to have been consistently determined by his ontology.