Reliability and Justified Belief

The central problem of epistemology is to give an account of when beliefs are justified. Traditional epistemological theories are ‘internalist’ in the sense that they make justification entirely a matter of what beliefs one has and what sensory states, mnemonic states, etc., one is in. But there is a currently popular move in epistemology to import ‘external’ considerations of reliability into matters of justification. The feeling is that if a particular belief forming mechanism is to issue in justified belief, then ‘surely it must be reliable.’ Thus it is proposed that reliability is either a necessary condition, or a sufficient condition, or both, for justified belief.