This paper attempts to take a new look at the famous Lewis Carroll paradox about Achilles and the Tortoise. It examines in particular the connections between Lewis Carroll's regress argument for logical inferences and a similar regress for practical inferences. The Tortoise's point of view is espoused: no norm of reasoning or of conduct can in itself "make the mind move," only the brute force of belief can. This conclusion is a Humean one. But it does not imply that we renounce altogether the normative force of such principles of reasoning as modus ponens. Connexions with the Wittgensteinian rule-following problem are indicated.