Abstract

Descartes’ demon is a crafty little devil. Despite centuries of effort by exceedingly clever thinkers, he continues to elude our clutches. Skepticism endures. The reason, Richard Foley thinks, is not hard to discover. It is simply impossible to break through the Cartesian circle. Our only means of vindicating a claim to knowledge or rational belief is to show that it is produced or sustained by our best epistemic methods, that it satisfies the best standards we can devise for rational belief. That it does so is clearly better than the alternative. But the standards and methods themselves are vulnerable. How do we know that they are reliable? The point, as we all realized in Philosophy 101, is that there is no ironclad guarantee. Even if Descartes had managed to generate an unexceptionable proof that God exists and is not a deceiver, the question would arise: What insures that what we consider an unexceptionable proof actually demonstrates the truth of the conclusion? Raising our standards or improving our methods of proof will not get us out of our predicament. For no matter how high we raise our standards, the question recurs. We cannot prove that our perceptions, memories, inferences or opinions are reliable. The Cartesian circle is the epistemic circle.