What The Tortoise Has To Say About Diachronic Rationality

Even if you believe just what you rationally ought to believe, you may be open to rational criticism if you do so ‘for the wrong reasons’, as we say. Some have thought that this familiar observation supports the idea that there are diachronic norms of epistemic rationality – namely, norms of good reasoning. Partly drawing upon Carroll's story of Achilles and the Tortoise, this article criticises this line of thought on the grounds that it rests on a mistaken conception of inference.