Transcendental arguments

Transcendental arguments seek to answer scepticism by showing that the things doubted by a sceptic are in fact preconditions for the scepticism to make sense. Hence the scepticism is either meaningless or false. A transcendental argument works by finding the preconditions of meaningful thought or judgment. For example, scepticism about other minds suggests that only the thinker themselves might have sensations. A transcendental argument which answered this scepticism would show that a precondition for thinking oneself to have sensations is that others do so as well. Expressing the scepticism involves thinking oneself to have sensations; and the argument shows that if this thought is expressible, then it is also false.

Arguments with such powerful consequences have, unsurprisingly, been much criticized. One criticism is that it is not possible to discover the necessary conditions of judgment. Another is that transcendental arguments can only show us how we have to think, whereas defeating scepticism involves showing instead how things really are.