It is extraordinary, when one thinks about it, how little attention has been paid by theorists of the nature and justification of punishment to the idea that punishment is essentially a matter of self-defense. H. L. A. Hart, for example, in his famous “Prolegomenon to the Principles of Punishment,” is clearly committed to the view that, at bottom, there are just three directions in which a plausible theory of punishment can go: we can try to justify punishment on purely consequentialist grounds, which for Hart, I think, would be to try to construct a purely utilitarian justification of punishment; we can try to justify punishment on purely retributive grounds; or we can try to justify punishment on grounds that are some sort of shrewd combination of consequentialist and retributive considerations. Entirely absent from Hart's discussion is any consideration of the possibility that punishment might be neither a matter of maximizing the good, nor of exacting retribution for a wrongful act, nor of some imaginative combination of these things, but, rather, of something altogether different from either of them: namely, the exercise of a fundamental right of self-protection. Similarly, but much more recently, R. A. Duff, despite the fact that he himself introduces and defends an extremely interesting fourth possibility, begins his discussion by writing as though, apart from his contribution, there are available to us essentially just the options previously sketched by Hart. Again, there is no mention here, any more than in Hart's or any number of other recent discussions, of the possibility that we might be able to justify the institution of punishment on grounds that are indeed forward-looking, to use Hart's famous term, but that are not at all consequentialist in any ordinary sense of the word.