Abstract:

On Certainty, as the most important work of Wittgenstein's late years, includes abundant thought of doubt. In it he holds that skeptical doubt is neither genuine nor meaningful, for it is short of a foundation of reasonable doubt and far away from the ordinary language game. It cannot build up relations of doubt and human activities, and completely overlooks and even denies those positive and unsuspecting elements of reasonable doubt. Wittgenstein's idea of doubt is theoretically based on practical foundationalism.

Key words: Wittgenstein, meaningful doubt, skepticism, practical foundationalism