Of the other Laws of Nature, treated in Chap. XV., the third, _that men perform their covenants made_, opens up the discussion of _Justice_. Till rights have been transferred and covenants made there is no justice or injustice; injustice is no other than the non-performance of covenants. Further, justice (and also property) begins only where a regular coercive power is constituted, because otherwise there is cause for fear, and fear, as has been seen, makes covenants invalid. Even the scholastic definition of justice recognizes as much; for there can be no constant will of giving to every man his own, when, as in the state of nature, there is no _own_. He argues at length against the idea that justice, _i.e._, the keeping of covenants, is contrary to reason; repelling three different arguments. (1) He demonstrates that it cannot be reasonable to break or keep covenants according to benefit supposed to be gained in each case, because this would be a subversion of the principles whereon society is founded, and must end by depriving the individual of its benefits, whereby he would be left perfectly helpless. (2) He considers it frivolous to talk of securing the happiness of heaven by any kind of injustice, when there is but one possible way of attaining it, viz., the keeping of covenants. (3) He warns men (he means his contemporaries) against resorting to the mode of injustice known as rebellion to gain sovereignty, from the hopelessness of gaining it and the uncertainty of keeping it. Hence he concludes that justice is a rule of reason, the keeping of covenants being the surest way to preserve our life, and therefore a law of nature. He rejects the notion that laws of nature are to be supposed conducive, not to the preservation of life on earth, but to the attainment of eternal felicity; whereto such breach of covenant as rebellion may sometimes be supposed a means. For that, the knowledge of the future life is too uncertain. Finally, he consistently holds that faith is to be kept with heretics and with all that it has once been pledged to.
He goes on to distinguish between justice of men or manners, and justice of actions; whereby in the one case men are _just_ or _righteous_, and in the other, _guiltless_. After making the common observation that single inconsistent acts do not destroy a character for justice or injustice, he has this: 'That which gives to human actions the relish of justice, is a certain nobleness or gallantness of courage rarely found, by which a man scorns to be beholden for the contentment of his life to fraud, or breach of promise.' Then he shows the difference between injustice, injury, and damage; asserts that nothing done to a mail with his consent can be injury; and, rejecting the common mode of distinguishing between _commutative_ and _distributive_ justice, calls the first the justice of a contractor, and the other an improper name for just distribution, or the justice of an arbitrator, _i.e._, the act of defining what is just--equivalent to equity, which is itself a law of nature.