Book 2
5
By the mean of the thing I denote a point equally distant from either extreme, which is one and the same for everybody; by the mean relative to us, that amount which is neither too much nor too little, and this is not one and the same for everybody.
6
For example, let 10 be many and 2 few; then one takes the mean with respect to the thing if one takes 6;
7
since 6 —2 = 10 — 6, and this is the mean according to arithmetical proportion.We should rather call this an arithmetical progression. But we cannot arrive by this method at the mean relative to us. Suppose that 10 lb. of food is a large ration for anybody and 2 lb. a small one: it does not follow that a trainer will prescribe 6 lb., for perhaps even this will be a large ration, or a small one, for the particular athlete who is to receive it; it is a small ration for a Milo,A famous wrestler. but a large one for a man just beginning to go in for athletics. And similarly with the amount of running or wrestling exercise to be taken.
8
In the same way then an expert in any art avoids excess and deficiency, and seeks and adopts the mean—the mean that is not of the thing but relative to us.
