ABSTRACT
This chapter introduces and defends the principle that “ought” implies “can”. It is suggested that the principle is a conceptual truth and convincingly explains many correct moral propositions. A recipe for defending “ought” implies “can” is introduced, which is inspired by R.M. Hare’s defence of utilitarianism. The recipe contains three instructions that, if followed carefully, can be used to defend “ought” implies “can” against any alleged counterexample: (i) ask for details, (ii) check the relevance of the peculiarities, and (iii) consider alternatives to the ought-statement. The recipe is used to defend “ought” implies “can” against three types of alleged counterexamples: straightforward counterexamples involving compulsive actions by sadists and kleptomaniacs, the case of self-imposed inability put forward by Walter Sinnott-Armstrong, and the transplant case presented by Peter A. Graham. Graham’s case receives the longest discussion and leads to suggestions about the moral relevance of social norms and practices.
