The unjust man [in this limited sense of the word], we say, is unfair, and that which is unjust is unfair.

Now, it is plain that there must be a mean which lies between what is unfair on this side and on that. And this is that which is fair or equal; for any act that admits of a too much and a too little admits also of that which is fair.

If then that which is unjust be unfair, that which is just will be fair, which indeed is admitted by all without further proof.

But since that which is fair or equal is a mean between two extremes, it follows that what is just will be a mean.

But equality or fairness implies two terms at least. 100