The aim of this article is to set out a theory for treatment of criminals that rejects retributive justification for punishment; does not fall afoul of a plausible prohibition on using people merely as means; and actually works in the real world. The theory can be motivated by free will skepticism. But it can also be supported without reference to the free will issue, since retributivism faces ethical challenges in its own right. In past versions of the account I’ve emphasized (...) the quarantine analogy for incapacitation together with the value of rehabilitation and reintegration. Here I pay special attention to the permissibility and the limits of general deterrence. (shrink)