ginary products of our perception? There are no easy answers to such questions, but it is clear that we must have some method of limiting and shaping the a priori statements, which serve as the cornerstones of our epistemology. Limiting A Priori Statements Descartes pioneered a method of limiting a priori statements, which is known as Cartesian Doubt. Descartes, following the rule of Cartesian Doubt, rejected all statements, which he did not know to be true beyond any and all doubt. He posited that the resulting few statements would then serve as the foundations for an all-encompassing epistemology. This approach led him to acknowledge that the only thing of which he could be absolutely sure was the existence of the doubt itself. From this he inferred that there must also exist an ego, a self, which could entertain such doubts. This, in turn, gave rise to what is probably the most well known philosophical statement of all time: "I think, therefore I am." The fundamental difficulty with this approach is that we can easily question (or doubt) the validity of Descartes' inference of a self. If Cartesian Doubt is our litmus test, then we must reject the inference of ego, simply because we can doubt the validity of the inference. So, Cartesian Doubt only allows us to accept the existence of doubt itself. Nothing more. Cartesian Doubt simply does not provide us with an adequate foundation on which to establish an epistemology. Having turned a critical eye on Cartesian Doubt, I now backtrack a little and say that I think Descartes was headed in the right direction. Descartes' mistake was simply in insisting on too strict a standard by which to allow for the validity of a priori statements. If nothing is allowed which some insistent skeptic, can doubt, then we are left with no basis for further progress. Therefore, I advocate a kind of Optimistic Skepticism in which we allow only those things, which are absolutely necessary for rational progres...
