(Cogito, ergo sum!) he might as well have said: Je sens, je veux, donc je suis!—The word “therefore” (donc, ergo) is inexact; for Descartes does not regard the proposition as a logical deduction, but as an immediate intuition, a simple intellectual step, through which we become conscious that we are conscious.—The clearness and distinctness of this intuition, according to Descartes, furnish the criterion by which to test other propositions. There are two more intuitions however which he thinks are just as clear and self-evident as this first one, namely the proposition that everything has a cause, and that the effect cannot be greater than the cause.
If we examine our different ideas, we find that some of them can be attributed to external and finite causes, and that others are produced by ourselves, but that there is one idea which presupposes an infinite cause—namely the idea of God. I am myself (which is proved by the fact that I can doubt) a finite, imperfect being, and I cannot therefore have formed the idea of an infinite, perfect being. This idea must have its origin in an infinite being. This is the only possible explanation of the fact that my intellect, as soon as it has attained mature development, forms this idea. It is “innate,” not indeed as if it were consciously present at the very beginning of life, but in the sense that there is a disposition to form it in the very nature of the intellect.—Descartes however has another proof of the existence of God: God, the perfect Being, must exist; for existence is perfection, hence the denial of the existence of God would be self-contradictory. This is the so-called ontological proof, which finds the warrant for the existence of God in the concept.
It is only after Descartes has established the validity of the idea of God (assuming the principle of causality as a