TRADITIONALLY there have been three arguments for the punishment of criminals. The first of these is that punishment is morally required or, another way of putting the same thing, that it is necessary for the community to feel morally satisfied. I will not discuss this further. The two remaining explanations are that punishment deters crime and that it may rehabilitate the criminal. The rehabilitation argument was little used before about 1800, presumably because the punishments in vogue up to that time had little prospect of producing any positive effect upon the moral character of the criminal.