ABSTRACT: The analytic method by which Descartes established the first principle of his philosophy is a unique cognitive process of direct insight and non-logical inference that differs markedly from the deductive model of noetic apprehension long associated with seventeenth-century rationalism. In this paper, it is shown that the same analytic process is at work in the Third Meditation proof of the innateness of the idea of God, where, however, there are serious doubts about its legitimacy.