Aristotle, Nicomachean Ethics
H. Rackham, Ed.

as a term of approval to other things besides what is just, and use it as the equivalent of ‘good,’ denoting by ‘more equitable’ merely that a thing is better. Yet at other times, when we think the matter out, it seems strange that the equitable should be praiseworthy if it is something other than the just. If they are different, either the just or the equitable is not good; if both are good, they are the same thing. [2]

These then are the considerations, more or less, from which the difficulty as to the equitable arises. Yet they are all in a manner correct, and not really inconsistent. For equity, while superior to one sort of justice, is itself just: it is not superior to justice as being generically different from it. Justice and equity are therefore the same thing, and both are good, though equity is the better. [3]

The source of the difficulty is that equity, though just, is not legal justice, but a rectification of legal justice. [4] The reason for this is that law is always a general statement, yet there are cases which it is not possible to cover in a general statement. In matters therefore where, while it is necessary to speak in general terms, it is not possible to do so correctly, the law takes into consideration the majority of cases, although it is not unaware of the error this involves. And this does not make it a wrong law; for the error is not in the law nor in the lawgiver, but in the nature of the case: the material of conduct is essentially irregular.