The requirements of rationality are fundamental in practical and theoretical philosophy. Nonetheless, there exists no correct account of what constitutes rational requirements. This paper attempts to provide a correct constitutive account of ‘rationality requires’. I argue that rational requirements are grounded in ‘necessary explanations of subjective incoherence’, as I shall put it. Rationality requires of you to X if and only if your rational capacities, in conjunction with the fact that you not-X, explain necessarily why you have a non-maximal degree (...) of subjective coherence. (shrink)