Aristotle, Nicomachean Ethics
H. Rackham, Ed.

are like standard measures. Corn and wine measures are not equal in all places, but are larger in wholesale and smaller in retail markets. Similarly the rules of justice ordained not by nature but by man are not the same in all places, since forms of government are not the same, though in all places there is only one form of government that is natural, namely, the best form. [6]

The several rules of justice and of law are related to the actions conforming with them as universals to particulars, for the actions done are many, while each rule or law is one, being universal. [7]

There is a difference between ‘that which is unjust’ and ‘unjust conduct,’ and between ‘that which is just’ and ‘just conduct.’ Nature or ordinance pronounces a thing unjust: when that thing is done, it is ‘unjust conduct’; till it is done, it is only ‘unjust.’ And similarly with ‘just conduct,’ a dikaioma （or more correctly, the general term is dikaiopragema, dikaioma denoting the rectification of an act of injustice）.

We shall have later¹ to consider the several rules of justice and of law, and to enumerate their various kinds and describe them and the things with which they deal.8.

Such being an account of just and unjust actions, it is their voluntary performance that constitutes just and unjust conduct. If a man does them involuntarily, he cannot be said to act justly, or unjustly, except incidentally, in the sense that he does an act which happens to be just or unjust. [2] Whether therefore an action is or is not an act of injustice, or of justice, depends on its voluntary or involuntary character. When it is involuntary, the agent is blamed, and only in that case is the action an act of injustice; so that it is possible for an act to be unjust without being an act of injustice, if the qualification of voluntariness be absent. [3] By a voluntary action, as has been said before,² I mean any action within the agent's own control which he performs knowingly, that is, without being in ignorance of the person affected, the instrument employed, and the result （for example, he must know whom he strikes, and with what weapon, and the effect of the blow）; and in each of these respects both accident³ and compulsion must be excluded. For instance, if A took hold of B's hand and with it struck C, B would not be a voluntary agent, since the act would not be in his own control. Or again, a man may strike his father without knowing that it is his father, though aware that he is striking some person, and perhaps that it is one or other of the persons present⁴; and ignorance may be similarly defined with reference to the result, and to the circumstances of the action generally. An involuntary act is therefore an act done in ignorance, or else one that though not done in ignorance is not in the agent's control, or is done under compulsion; since there are many natural processes too