Abstract

In the Metaphysics of Morals Kant clearly, and indeed ardently, upholds the state's right to impose the death penalty in accordance with the law of retribution (ius talionis). The “principle of equality” as between crime and punishment demands that those who wrongfully kill another should be put to death, for, in having inflicted such an evil upon another, the murderer has effectively killed himself. Kant is quite emphatic on this point: those who have committed murder “must die”. Here, he argues, “there is no substitute that will satisfy justice”, for there “is no similarity between life, however wretched it may be, and death, hence no likeness between the crime and the retribution unless death is judicially carried out upon the wrongdoer […]”. The ius talionis is, for Kant, the basic principle and measure in accordance with which criminal justice functions. Since the ius talionis entails a strict equality between crime and punishment, Kant's insistence that only the death penalty serves as the appropriate response to murder (or to any other equally egregious crime) is fairly straightforward.