Nicomachean Ethics

But the object of our enquiry is Justice, in the sense in which it is a part of Virtue (for there is such a thing, as we commonly say), and likewise with respect to particular Injustice. And of the existence of this last the following consideration is a proof: there are many vices by practising which a man acts unjustly, of course, but does not grasp at more than his share of good; if, for instance, by reason of cowardice he throws away his shield, or by reason of ill-temper he uses abusive language, or by reason of stinginess does not give a friend pecuniary assistance; but whenever he does a grasping action, it is often in the way of none of these vices, certainly not in all of them, still in the way of some vice or other (for we blame him), and in the way of Injustice. There is then some kind of Injustice distinct from that co-extensive with Vice and related to it as a part to a whole, and some “Unjust” related to that which is co-extensive with violation of the law as a part to a whole.

Again, suppose one man seduces a man’s wife with a view to gain and actually gets some advantage by it,[6] and another does the same from impulse of lust, at an expense of money and damage; this latter will be thought to be rather destitute of self-mastery than a grasping man, and the former Unjust but not destitute of self-mastery: now why? plainly because of his gaining.

Again, all other acts of Injustice we refer to some particular depravity, as, if a man commits adultery, to abandonment to his passions; if he deserts his comrade, to cowardice; if he strikes another, to anger: but if he gains by the act to no other vice than to Injustice.

Thus it is clear that there is a kind of Injustice different from and besides that which includes all Vice, having the same name because the definition is in the same genus; for both have their force in dealings with others, but the one acts upon honour, or wealth, or safety, or by whatever one name we can include all these things, and is actuated by pleasure attendant on gain, while the other acts upon all things which constitute the sphere of the good man’s action.