Will, Certainty, God

Since valid proof is truth-preserving, it is also certainty-preserving. Thus, Descartes adheres, at least in principle, to his method, as he first certifies 'I am', and then, derives from it 'God exists'. At that juncture, however, he abandons any method, by first affirming that 'God is good', and, then, that 'A good God would not deceive me'. The first is problematic, since he has not submitted 'is good' to any methodical examination. The second is problematic, since, even granting the first, that a good God would not deceive him for his own good is groundless. Now, it is unclear whether Descartes' acceptance at this juncture of dogma that he had previously called into question is sincere or is an expression of prudence under hostile conditions. Regardless, what he demonstrates is that what he henceforth accepts--the laws of Mathematics, the existence of the physical world, etc.--are meaningful only as the beliefs of an cogitating 'I', i. e. as structures that supply Will with determinacy.