The Skeptic and the Dogmatist

Consider the skeptic about the external world. Let’s straightaway concede to such a skeptic that perception gives us no conclusive or certain knowledge about our surroundings. Our perceptual justification for beliefs about our surroundings is always defeasible—there are always possible improvements in our epistemic state which would no longer support those beliefs. Let’s also concede to the skeptic that it’s metaphysically possible for us to have all the experiences we’re now having while all those experiences are false. Some philosophers dispute this, but I do not. The skeptic I want to consider goes beyond these familiar points to the much more radical conclusion that our perceptual experiences can’t give us any knowledge or even justification for believing that our surroundings are one way rather than another. One might go about grappling with such a skeptic in two different ways. The ambitious anti-skeptical project is to refute the skeptic on his own terms, that is, to establish that we can justifiably believe and know such things as that there is a hand, using only premises that the skeptic allows us to use. The prospects for this ambitious anti-skeptical project seem somewhat dim. The modest anti-skeptical project is to establish to our satisfaction that we can justifiably believe and know such things as that there is a hand, without contradicting obvious facts about perception. This is not easy to do, for the skeptic can present us with arguments from premises we find intuitively acceptable to the conclusion that we cannot justifiably believe or know such things. So we have a problem: premises we find plausible seem to support a conclusion we find unacceptable. The modest anti-skeptical project attempts to diagnose and defuse those skeptical arguments; to show how to retain as many of our pretheoretical beliefs about perception as possible, without accepting the premises the skeptic needs for his argument. Since this modest anti-skeptical project just NOÛS 34:4 ~2000! 517–549