If you justifiably believe that you ought to Φ, you ought to Φ

In this paper, we claim that, if you justifiably believe that you ought to perform some act, it follows that you ought to perform that act. In the first half, we argue for this claim by reflection on what makes for correct reasoning from beliefs about what you ought to do. In the second half, we consider a number of objections to this argument and its conclusion. In doing so, we arrive at another argument for the view that justified beliefs about what you ought to do must be true, based in part on the idea that the epistemic and practical domains are uniform, in a sense we spell out. We conclude by sketching possible implications of our discussion for the debates over what is wrong with akrasia and pragmatic encroachment on justified belief and knowledge.