Skepticism, fallibilism and empiricism

Critics often argue that empiricism cannot account for obvious cases of knowledge and so implies skepticism. In general, a skeptic about a certain domain of beliefs (e.g. the external world, induction, religious belief) denies that we have knowledge in that area. He need not deny that the propositions are true, but only that we cannot know that they are. He is also not committed to holding that we should not believe them. Skepticism is a purely epistemic judgement about the quality of our evidence. What might be called ‘general skepticism’ is the view that we have no knowledge at all, not even knowledge that we have none.

The question of skepticism obviously turns on the meaning of ‘knowledge’. Traditionally, knowledge has been taken to imply that we cannot be mistaken in the sense that our evidence must be stronger than even the highest probability, so that ‘probable knowledge’ is contradictory. Since we no longer accept this, it is better to use ‘absolute certainty’ (or just ‘certainty’) for the traditional sense and take ‘knowledge’ to be the more inclusive term. To be certain that p is to be justified beyond all possible (i.e. imaginary) doubt, while to have knowledge is to be justified beyond reasonable doubt.

We can then distinguish four doctrines: fallibilism (the thesis that nothing is absolutely certain), skepticism (that nothing is known to be true), and their negations, infallibilism (something is certain) and what we might label common-sensism (something is known to be true).