Naturalism, as Binmore understands the term, is characterized by a scientific stance on moral behavior. Binmore claims that a naturalistic account of morality necessarily goes with the conviction “that only hypothetical imperatives make any sense”. In this paper it is argued that this claim is mistaken. First, as Hume’s theory of promising shows, naturalism in the sense of Binmore is very well compatible with acknowledging the importance of categorical imperatives in moral practice. Moreover, second, if Binmore’s own theory of moral practice and its evolution is correct, then the actual moral practice does-and in fact must-incorporate norms, which have the form of a categorical imperative. Categorical imperatives are part of social reality and, therefore, any (normative) moral theory that adequately reflects moral practice must also include categorical imperatives.