God exists. (8) Having proved to his own satisfaction that God exists, Descartes proceeds to show that He is the creator of man. (9) But the infinitely perfect God cannot be a deceiver; consequently, He cannot have given man deceptive powers of knowledge, and man's faculties are thus shown to be trustworthy, "provided we separate what there is of clear and distinct in the knowledge from what is obscure and confused." (10) In the light of this criterion of "clear and distinct" knowledge all previous doubts about the world, sense-perception, and intellection must vanish. Skepticism is defeated, and valid knowledge is possible.The Failure of Descartes' MethodDescartes' fundamental purpose was laudable; he desired to defend human knowledge against the attacks of skeptics. Generally speaking, he was justified in demanding that the investigation into the nature and limits of knowledge exclude preconceived ideas, traditional doctrines, and unwarranted presuppositions as evidence and proof, since the validity of all spontaneous convictions was at stake.But when he proposed to approach the problem in an attitude of universal real doubt, discarding even the capability of the human mind to know truth and refusing to accept such essential principles as the principle of contradiction and the principle of sufficient reason, he made the solution of the problem impossible for himself. Here are a few considerations which compel us to reject his system.Descartes began his inquiry by doubting all knowledge without exception; he was even willing to accept it as "entirely false." This being the case, what about the idea of God as an all-perfect Being, since he admits that he discovered this idea in his own mind? According to his own principle of universal doubt, he simply cannot know whether this idea of God is correct or incorrect; as a matter of fact, according to this principle, he should consider it as "entirely false," until proved otherwise. But if h...
