not the sole foundation of public punishment, it is yet inseparable from that public interest, on which the system of rights, with the corresponding system of punishments protective of rights, depends. In whatever sense then this indignation demands retribution in punishment, in that sense retribution would seem to be a necessary element in punishment. It demands retribution in the sense of demanding that the criminal should have his due, should be dealt with according to his deserts, should be punished justly. 184. This is quite a different thing from an equivalence between the amount of suffering inflicted by the criminal and that which he sustains in punishment. The amount of suffering which is caused by any crime is really as incalculable as that which the criminal endures in punishment, whatever the punishment. It is only in the case of death for murder that there is any appearance of equivalence between the two sufferings, and in this case the appearance is quite superficial. The suffering involved in death depends almost entirely on the circumstances, which are absolutely different in the case of the murdered man and in that of the man executed for murder. When a man is imprisoned with hard labour for robbery, there is not even an appearance of equivalence of suffering between the crime and the punishment. In what then does the justice of a punishment, or its correspondence with the criminal's deserts consist? It will not do to say that these terms merely represent the result of an association of ideas between a crime and the penalty which we are accustomed to see inflicted on it; that society has come to attach certain penalties to certain actions as a result of the experience (1) of suffering and loss caused by those acts, and (2) of the kind of suffering of which the expectation will deter men from doing them; and that these penalties having become customary, the onlookers and the criminal himself, when one of them is inflicted, feel that he has got what was to be expected, and call it his due or desert or a just punishment. If this were the true account of the matter, there would be nothing to explain the difference between the emotion excited by the spectacle of a just punishment inflicted, or the demand that it should be inflicted, on the one side, and on the other that excited by the sight of physical suffering following according to the usual course of things upon a physical combination of circumstances, or the expectation that such suffering will follow. If it is said that the difference is explained by the fact that in the one case both the antecedent (the criminal act) and the consequent represent voluntary human agency, while in the other they do not, we reply, Just so, but for that reason the conception of a punishment as just differs wholly from any conception of it that could result either from its being customary, or from the infliction of such punishment having been commonly found a means for protecting us against hurt.