Aristotle: A Treatise on Government

BOOK III 9. CHAPTER IX

Let us first determine what are the proper limits of an oligarchy and a democracy, and what is just in each of these states; for all men have some natural inclination to justice; but they proceed therein only to a certain degree; nor can they universally point out what is absolutely just; as, for instance, what is equal appears just, and is so; but not to all; only among those who are equals: and what is unequal appears just, and is so; but not to all, only amongst those who are unequals; which circumstance some people neglect, and therefore judge ill; the reason for which is, they judge for themselves, and every one almost is the worst judge in his own cause. Since then justice has reference to persons, the same distinctions must be made with respect to persons which are made with respect to things, in the manner that I have already described in my Ethics.

As to the equality of the things, these they agree in; but their dispute is concerning the equality of the persons, and chiefly for the reason above assigned; because they judge ill in their own cause; and also because each party thinks, that if they admit what is right in some particulars, they have done justice on the whole: thus, for instance, if some persons are unequal in riches, they suppose them unequal in the whole; or, on the contrary, if they are equal in liberty, they suppose them equal in the whole: but what is absolutely just they omit; for if civil society was founded for the sake of preserving and increasing property, every one's right in the city would be equal to his fortune; and then the reasoning of those who insist upon an oligarchy would be valid; for it would not be right that he who contributed one mina should have an equal share in the hundred along with him who brought in all the rest, either of the original money or what was afterwards acquired.