This paper is a defence of T.M. Scanlon's contractualism - the view that an action is wrong if it is forbidden by the principles which no one could reasonably reject. Such theories have been argued to be redundant in two ways. They are claimed to assume antecedent moral facts to explain which principles could not be reasonably rejected, and the reasons they provide to follow the non-rejectable principles are said to be unnecessary given that we already have sufficient reasons not (...) to do the acts that are forbidden by those principles. In this paper, I try to argue that neither one of these claims is true. (shrink)