[1373b] It will now be well to make a complete classification of just and unjust actions. We may begin by observing that they have been defined relatively to two kinds of law, and also relatively to two classes of persons. By the two kinds of law I mean particular law and universal law. Particular law is that which each community lays down and applies to its own members: this is partly written and partly unwritten. Universal law is the law of Nature. For there really is, as every one to some extent divines, a natural justice and injustice that is binding on all men, even on those who have no association or covenant with each other. It is this that Sophocles' Antigone clearly means when she says that the burial of Polyneices was a just act in spite of the prohibition: she means that it was just by nature.
And so Empedocles, when he bids us kill no living creature, says that doing this is not just for some people while unjust for others,
And as Alcidamas says in his Messeniac Oration. . . .
The actions that we ought to do or not to do have also been divided into two classes as affecting either the whole community or some one of its members. From this point of view we can perform just or unjust acts in either of two ways -- towards one definite person, or towards the community. The man who is guilty of adultery or assault is doing wrong to some definite person; the man who avoids service in the army is doing wrong to the community.
Thus the whole class of unjust actions may be divided into two classes, those affecting the community, and those affecting one or more other persons. We will next, before going further, remind ourselves of what "being wronged" means. Since it has already been settled that "doing a wrong" must be intentional, "being wronged" must consist in having an injury done to you by some one who intends. to do it. In order to be wronged, a man must (1) suffer actual harm, (2) suffer it against his will. The various possible forms of harm are clearly explained by our previous, separate discussion of goods and evils. We have also seen that a voluntary action is one where the doer knows what he is doing. We now see that every accusation must be of an action affecting either the community or some individual. The doer of the action must either understand and intend the action, or not understand and intend it. In the former case, he must be acting either from deliberate choice or from passion. (Anger will be discussed when we speak of the passions the motives for crime and the state of mind of the criminal have already been discussed.) [1374a] Now it often happens that a man will admit an act, but will not admit the prosecutor's label for the act nor the facts which that label implies. He will admit that he took a thing but not that he "stole" it; that he struck some one first, but not that he committed "outrage"; that he had intercourse with a woman, but not that he committed "adultery"; that he is guilty of theft, but not that he is guilty of "sacrilege," the object stolen not being consecrated; that he has encroached, but not that he has "encroached on State lands"; that he has been in communication with the enemy, but not that he has been guilty of "treason." Here therefore we must be able to distinguish what is theft, outrage, or adultery, from what is not, if we are to be able to make the justice of our case clear, no matter whether our aim is to establish a man's guilt or to establish his innocence. Wherever such charges are brought against a man, the question is whether he is or is not guilty of a criminal offence. It is deliberate purpose that constitutes wickedness and criminal guilt, and such names as "outrage" or "theft" imply deliberate purpose as well as the mere action. A blow does not always amount to "outrage," but only if it is struck with some such purpose as to insult the man struck or gratify the striker himself. Nor does taking a thing without the owner's knowledge always amount to "theft," but only if it is taken with the intention of keeping it and injuring the owner. And as with these charges, so with all the others.
We saw that there are two kinds of right and wrong conduct towards others, one provided for by written ordinances, the other by unwritten. We have now discussed the kind about which the laws have something to say. The other kind has itself two varieties. First, there is the conduct that springs from exceptional goodness or badness, and is visited accordingly with censure and loss of honour, or with praise and increase of honour and decorations: for instance, gratitude to, or requital of, our benefactors, readiness to help our friends, and the like. The second kind makes up for the defects of a community's written code of law. This is what we call equity; people regard it as just; it is, in fact, the sort of justice which goes beyond the written law. Its existence partly is and partly is not intended by legislators; not intended, where they have noticed no defect in the law; intended, where find themselves unable to define things exactly, and are obliged to legislate as if that held good always which in fact only holds good usually; or where it is not easy to be complete owing to the endless possible cases presented, such as the kinds and sizes of weapons that may be used to inflict wounds -- a lifetime would be too short to make out a complete list of these. If, then, a precise statement is impossible and yet legislation is necessary, the law must be expressed in wide terms; and so, if a man has no more than a finger-ring on his hand when he lifts it to strike or actually strikes another man, he is guilty of a criminal act according to the unwritten words of the law; [1374b] but he is innocent really, and it is equity that declares him to be so. From this definition of equity it is plain what sort of actions, and what sort of persons, are equitable or the reverse. Equity must be applied to forgivable actions; and it must make us distinguish between criminal acts on the one hand, and errors of judgement, or misfortunes, on the other. (A "misfortune" is an act, not due to moral badness, that has unexpected results: an "error of judgement" is an act, also not due to moral badness, that has results that might have been expected: a "criminal act" has results that might have been expected, but is due to moral badness, for that is the source of all actions inspired by our appetites.) Equity bids us be merciful to the weakness of human nature; to think less about the laws than about the man who framed them, and less about what he said than about what he meant; not to consider the actions of the accused so much as his intentions, nor this or that detail so much as the whole story; to ask not what a man is now but what he has always or usually been. It bids us remember benefits rather than injuries, and benefits received rather than benefits conferred; to be patient when we are wronged; to settle a dispute by negotiation and not by force; to prefer arbitration to litigation -- for an arbitrator goes by the equity of a case, a judge by the strict law, and arbitration was invented with the express purpose of securing full power for equity.
The above may be taken as a sufficient account of the nature of equity.