iv.1.1 We must examine justice and injustice, the kinds of actions that they are concerned with, the kind of mean point that justice is, and what it is a mean between. iv.1.2 Let our investigation use the same method as our preceding discussions.
iv.1.3 Now we see that everyone wishes to speak of justice as the kind of state that makes people inclined to do just deeds, to act justly, and to wish for what is just. Injustice is spoken of in the same manner, as that which makes people do injustice and wish for what is unjust. So let this be laid down as our initial outline too.
iv.1.4 There is a disanalogy between kinds of knowledge and capacities on the one hand, and states on the other. It seems that with a capacity or a kind of knowledge, the same one encompasses opposites, whereas any state that is opposite to another does not encompass opposites. For example, opposite outcomes do not result from health, only healthy ones, since we say that someone walks healthily whenever he walks as a healthy person would.