PD31. The justice which arises from nature is a pledge of mutual advantage, to restrain men from harming one another, and save them from being harmed.
PD32. For all living things which have not been able to make compacts not to harm one another, or be harmed, nothing ever is either just or unjust; and likewise, too, for all tribes of men which have been unable, or unwilling, to make compacts not to harm or be harmed.
PD33. Justice never is anything in itself, but in the dealings of men with one another, in any place whatever, and at any time, it is a kind of compact not to harm or be harmed.
PD34. Injustice is not an evil in itself, but only in consequence of the fear which attaches to the apprehension of being unable to escape those appointed to punish such actions.
PD35. It is not possible for one who acts in secret contravention of the terms of the compact not to harm or be harmed to be confident that he will escape detection, even if, at present, he escapes a thousand times. For up to the time of death it cannot be certain that he will indeed escape.
PD36. In its general aspect, justice is the same for all, for it is a kind of mutual advantage in the dealings of men with one another; but with reference to the individual peculiarities of a country, or any other circumstances, the same thing does not turn out to be just for all.
PD37. Among actions which are sanctioned as just by law, that which is proved, on examination, to be of advantage, in the requirements of men's dealings with one another, has the guarantee of justice, whether it is the same for all or not. But if a man makes a law, and it does not turn out to lead to advantage in men's dealings with each other, then it no longer has the essential nature of justice. And even if the advantage in the matter of justice shifts from one side to the other, but for a while accords with the general concept, it is nonetheless just for that period, in the eyes of those who do not confound themselves with empty sounds, but look to the actual facts.
PD38. Where, provided the circumstances have not been altered, actions which were considered just have been shown not to accord with the general concept, in actual practice, then they are not just. But where, when circumstances have changed, the same actions which were sanctioned as just no longer lead to advantage, they were just at the time, when they were of advantage for the dealings of fellow-citizens with one another, but subsequently they are no longer just, when no longer of advantage.