Can a Justified Belief Be False?

Abstract

Edmund Gettier objects to analysing knowledge as justified true belief (JTB) on the ground that someone can justifiably infer a true conclusion from a justified false premise and hence not know the conclusion's truth, although the conclusion is justified. For instance, someone can justifiably deduce a true p v r from a justified but false p, where he has no justification for the true r. Gettier's objection draws on two assumptions: first, that a justified belief can be false; second, that a premise can justify a conclusion even though the premise is false.Some JTB advocates grant the first assumption but deny the second. They usually concede the first assumption to protect the respectability of non-deductive inference. The argument is that if evidence e can nondeductively justify the conclusion c, then it must be possible for c to be justified and yet false, since e does not entail c. Although the assumption is sound, the argument as it stands fails to show it. But let us set this point aside for the moment.