Aristotle, Nicomachean Ethics
H. Rackham, Ed.

[11] but if a man does an injury of set purpose, he is guilty of injustice, and injustice of the sort that renders the doer an unjust man, if it be an act that violates proportion or equality. Similarly one who acts justly on purpose is a just man; but he acts justly only if he acts voluntarily. [12]

Of involuntary actions some are pardonable and some are not. Errors not merely committed in ignorance but caused by ignorance are pardonable; those committed in ignorance, but caused not by that ignorance but by unnatural or inhuman passion, are unpardonable.9.

But it may perhaps be doubted whether our discussion of suffering and doing injustice has been sufficiently definite; and in the first place, whether the matter really is as Euripides has put it in the strange lines¹— “ I killed my mother—that's the tale in brief!
Were you both willing, or unwilling both?

” Is it really possible to suffer injustice² voluntarily, or on the contrary is suffering injustice always involuntary, just as acting unjustly is always voluntary? And again, is suffering injustice always voluntary, or always involuntary, or sometimes one and sometimes the other? [2] And similarly with being treated justly （acting justly being always voluntary）. Thus it would be reasonable to suppose that both being treated unjustly and being treated justly are similarly opposed to acting unjustly and acting justly respectively: that either both are voluntary or both involuntary. But it would seem paradoxical to assert that even being treated justly is always voluntary; for people are sometimes treated justly against their will. [3] The fact is that the further question might be raised, must a man who has had an unjust thing done to him always be said to have been treated unjustly, or does the same thing hold good of suffering as of doing something unjust? One may be a party to a just act, whether as its agent or its object, incidentally.³ And the same clearly is true of an unjust act: doing what is unjust is not identical with acting unjustly, nor yet is suffering what is unjust identical with being treated unjustly, and the same is true of acting and being treated justly; for to be treated unjustly requires someone who acts unjustly, and to be treated justly requires someone who acts justly. [4]

But if to act unjustly is simply to do harm voluntarily, and voluntarily means knowing the person affected, the instrument, and the manner of injury, it will follow both that the man of defective self-restraint, inasmuch as he voluntarily harms himself, voluntarily suffers injustice, and also that it is possible for a man to act unjustly towards himself