one thing, and also from agreement (for which reason it is called νόμισμα), for this makes all things commensurable: in fact, all things are measured by money. Let B represent ten minæ, A a house worth five minæ, or in other words half B, C a bed worth 1/10th of B: it is clear then how many beds are equal to one house, namely, five.
It is obvious also that exchange was thus conducted before the existence of money: for it makes no difference whether you give for a house five beds or the price of five beds.
Chapter IX.
We have now said then what the abstract Just and Unjust are, and these having been defined it is plain that just acting is a mean between acting unjustly and being acted unjustly towards: the former being equivalent to having more, and the latter to having less.
But Justice, it must be observed, is a mean state not after the same manner as the forementioned virtues, but because it aims at producing the mean, while Injustice occupies both the extremes.