Justifying Deduction

Abstract

Is there a problem about justifying deduction? Why shouldn't there be? There is, after all, a direct analogue of Hume's dilemma for induction which applies, presumably with equal force, to deduction: We cannot justify deduction inductively since it would be far too weak to say, what such a justification could at best say, that usually when the premisses of a valid deductive argument are true, then the conclusion is true as well. But neither can we justify deduction deductively, because such ajustification would be circular. This much, it seems to me, is enough to think the issue worth raising. But if there is a genuine concern here, it is safe to say that few philosophers have paused long to worry about it. One of the reasons for this is that with the exception of Sextus Empiricus, J.S. Mill and a few others, philosophers have not been willing to entertain the notion that there is, or even that there could be, anything drastically wrong with deductive reasoning.