Since in every art and science the end aimed at is always good, so particularly in this, which is the most excellent of all, the founding of civil society, the good wherein aimed at is justice; for it is this which is for the benefit of all. Now, it is the common opinion, that justice is a certain equality; and in this point all the philosophers are agreed when they treat of morals: for they say what is just, and to whom; and that equals ought to receive equal: but we should know how we are to determine what things are equal and what unequal; and in this there is some difficulty, which calls for the philosophy of the politician. Some persons will probably say, that the employments of the state ought to be given according to every particular excellence of each citizen, if there is no other difference between them and the rest of the community, but they are in every respect else alike: for justice attributes different things to persons differing from each other in their character, according to their respective merits. But if this is admitted to be true, complexion, or height, or any such advantage will be a claim for a greater share of the public rights. But that this is evidently absurd is clear from other arts and sciences; for with respect to musicians who play on the flute together, the best flute is not given to him who is of the best family, for he will play never the better for that, but the best instrument ought to be given to him who is the best artist.

If what is now said does not make this clear, we will explain it still further: if there should be any one, a very excellent player on the flute, but very deficient in family and beauty, though each of them are more valuable endowments than a skill in music, and excel this art in a higher degree than that player excels others, yet the best flutes ought to be given to him; for the superiority [1283a] in beauty and fortune should have a reference to the business in hand; but these have none. Moreover, according to this reasoning, every possible excellence might come in comparison with every other; for if bodily strength might dispute the point with riches or liberty, even any bodily strength might do it; so that if one person excelled in size more than another did in virtue, and his size was to qualify him to take place of the other's virtue, everything must then admit of a comparison with each other; for if such a size is greater than virtue by so much, it is evident another must be equal to it: but, since this is impossible, it is plain that it would be contrary to common sense to dispute a right to any office in the state from every superiority whatsoever: for if one person is slow and the other swift, neither is the one better qualified nor the other worse on that account, though in the gymnastic races a difference in these particulars would gain the prize; but a pretension to the offices of the state should be founded on a superiority in those qualifications which are useful to it: for which reason those of family, independency, and fortune, with great propriety, contend with each other for them; for these are the fit persons to fill them: for a city can no more consist of all poor men than it can of all slaves But if such persons are requisite, it is evident that those also who are just and valiant are equally so; for without justice and valour no state can be supported, the former being necessary for its existence, the latter for its happiness.