.

             From this unquestioned fact a reasonable conclusion can be drawn in favor of the superior deterrent effect of the death penalty. Those who have the choice in practice, those whose choice has actual and immediate effects on their life and death, fear death more than they fear life in prison or any other available penalty. If they do, it follows that the threat of the death penalty, all other things equal, is likely to deter more than the threat of life in prison. One is most deterred by what one fears most. From which it follows that whatever statistics fail, or do not fail, to show, the death penalty is likely to be more deterrent than any other. Suppose now one is not fully convinced of the superior deterrent effect of the death penalty. I believe I can show that even if one is genuinely uncertain as to whether the death penalty adds to deterrence, one should still favor it, from a purely deterrent viewpoint. For if we are not sure, we must choose either to (1) trade the certain death, by execution, of a convicted murderer for the probable survival of an indefinite number of murder victims whose future murder is less likely (whose survival is more likely), if the convicted murderer's execution deters prospective murderers, as it might, or to (2) trade the certain survival of the convicted murderer for the probable loss of the lives of future murder victims more likely to be murdered because the convicted murderer's non-execution might not deter prospective murderers, who could have been deterred by executing the convicted murderer. .

             To restate the matter: If we were quite ignorant about the marginal deterrent effects of execution, we would have to choose, like it or not, between the certainty of the convicted murderer's death by execution and the likelihood of the survival of future victims of other murderers on the one hand, and on the other his certain survival and the likelihood of the death of new victims.