Abstract
This chapter begins with an examination of Dretske's important article “Conclusive Reasons.” Dretske's key move is to offer a subjunctive analysis of his notion of a conclusive reason: “R is a conclusive reason for P if and only if R would not be the case unless P were the case.” It seems, however, that a counterexample produced by Martin shows that while this biconditional holds left to right, it does not hold right to left. Dretske uses his analysis conclusive reasons to deny the principle of epistemic closure under known implication. He then uses this result in a response to skepticism. Reasons are given for rejecting his argument against epistemic closure. Nozick offers essentially the same subjunctive analysis that Dretske did, wrapped in possible‐world semantics. It is rejected on similar grounds.