PUNISHMENT, in the sense of penal sanction, is justified by its relative necessity, although certain pseudo-philosophers think that neither this nor any other principle can permit the use of such a barbarous institution. The justification of punishment by necessity would be too apparent to need proof, however, in spite of such allegations except that, as the categorical recognition of a truth is always an advance in knowledge, so the categorical recognition of this truth prepares the way for a clear understanding of the bases of punishment and is a long step on the road to the reform of criminal law. Punishment is relatively necessary, because society must protect itself -the right of self-defence cannot be denied. It is axiomatic. Society protects itself in two ways: (1) From external attacks of all agents or forces except man, by eliminatory and preventative acts; (2) from internal attacks of its members by penal sanctions or punishment, another form of defence, contra-distinguished from defence against foreign attack in being directed against fellow-human beings, who enjoy the use of reason, and to whom punishment will bring a psychic reaction. Punishment is, therefore, addressed to the reason of the criminal, which adds peculiar elements and qualities to such defensive action, lacking in the purely eliminatory or preventative reaction to foreign attack. Thus the right of society to punish is that of any being or entity to protect itself and corresponds to the duty of the member to comport himself in accordance with the rules, and to the best interest, of the association of whose benefits he partakes. This requirement limits the applicability of criminal law to members of one society. Reciprocity of rights and duties between groups is impossible, until, notwithstanding