Retribution justification requires a certain outcome on the issue of whether capital punishment does or does not deter offenses: capital punishment must be shown to have a positive deterrent effect on violent crime. If capital punishment were to increase violent crime, additional innocent victims would, in effect, be punished. This effect is unacceptable under retribution theory as defined by Kant, according to which persons who do not deserve to be punished cannot be punished. Whether society is returned to a people of equals, a second requirement of retribution theory, must be determined according to the positive or negative deterrent effect of capital punishment. The final argument used in retribution theory, denunciation, requires analysis of the effects of capital punishment to ascertain whether the punishers have been satisfied. While retributivists may consciously believe that capital punishment is justified because certain offenders deserve it, that belief is in part based on the unconscious belief that capital punishment deters. A total of 57 notes are supplied.