I shall address two concerns in this paper: first, what retributivism is, and second, how one justifies retributivism as the only proper theory of punishment. Since this paper is necessarily short, treatment of these topics is likewise abbreviated, although hopefully not so abbreviated but that it whets the appetite for those who wish to pursue them in greater depth.
Retributivism is the view that we ought to punish offenders because and only because they deserve to be punished. Punishment is justified, for a retributivist, solely by the fact that those receiving it deserve it. Punishment of deserving offenders may produce beneficial consequences other than giving offenders their just deserts. Punishment may deter future crime, incapacitate dangerous persons, educate citizens in the behavior required for a civilized society, reinforce social cohesion, prevent vigilante behavior, make victims of crime feel better, or satisfy the vengeful desires of citizens who are not themselves crime victims.