On some accounts, punishment is justified by the good results that it brings about. In particular, punishment deters, incapacitates, and may, in some cases, rehabilitate criminals. On a retributivist theory, punishment is not justified on the basis of these desirable results, but rather on the fact that the wrongdoer has done something that deserves punishment. In Desert, Retribution, and Torture, Stephen Kershnar provides an in-depth defense of retributivism. Kershnar then uses this theory to provide support for the notion that very harsh forms of punishment, including torture, are morally justified.