A Neo-Russellian Defence of Knowledge as Justified True Belief

Abstract: Accepting the Theaetetus definition of knowledge as fully justified true belief, Russell offered cases designed to reveal that true belief is not sufficient for knowledge. A belief mustn't be obtained via good reasoning from a false premise— even if the false premise is justified . Gettier cases raised suspicion that a fourth condition beyond justification is required. No adequate fourth condition has been found. This paper offers a neo-Russellian solution. The premises used in good reasoning must themselves carry over, so that what is justified is a conjunction of the premises together with the outcome of the reasoning. For example, justification that p does not entail justification of the disjunction p or q . It justifies the conjunction: p and ( p or q ). If p is false, the conjunction does not satisfy the truth-condition of the Theaetetus definition. This solution relies on Russell's insights to determine which premises relevantly carry over, and to expose the mirage that presents justification as if it distributes over conjunction.