_Sokr._--You think philosophy a fine thing? But you cannot tell whether it is fine or not, unless you know what it is.[5] Pray explain to me what philosophy is. _Erast._--I will do so readily. Philosophy consists in the perpetual growth of a man's knowledge--in his going on perpetually acquiring something new, both in youth and in old age, so that he may learn as much as possible during life. Philosophy is polymathy.[6] _Sokr._--You think philosophy not only a fine thing, but good? _Erast._--Yes--very good. _Sokr._--But is the case similar in regard to gymnastic? Is a man's bodily condition benefited by taking as much exercise, or as much nourishment, as possible? Is such very great quantity good for the body?[7] [Footnote 5: Plat. Erast. 133 A-B.] [Footnote 6: Plato, Erast. 133 D. [Greek: tê\n philosophi/an--poluma/theian.]] [Footnote 7: Plato, Erast. 133 E.] [Side-note: In the case of the body, it is not the maximum of exercise which does good, but the proper, measured quantity. For the mind also, it is not the maximum of knowledge, but the measured quantity which is good. Who is the judge to determine this measure?] It appears after some debate (in which the other or athletic Erastes sides with Sokrates[8]) that in regard to exercise and food it is not the great quantity or the small quantity, which is good for the body--but the moderate or measured quantity.[9] For the mind, the case is admitted to be similar. Not the _much_, nor the _little_, of learning is good for it but the right or measured amount. _Sokr._--And who is the competent judge, how much of either is right measure for the body? _Erast._--The physician and the gymnastic trainer. _Sokr._--Who is the competent judge, how much seed is right measure for sowing a field? _Erast._--The farmer. _Sokr._--Who is the competent judge, in reference to the sowing and planting of knowledge in the mind, which varieties are good, and how much of each is right measure? [Footnote 8: Plat. Erast. 134 B-C. The literary Erastes says to Sokrates, "To _you_, I have no objection to concede this point, and to admit that my previous answer must be modified. But if I were to debate the point only with _him_ (the athletic rival), I could perfectly well have defended my answer, and even worse answer still, for _he_ is quite worthless ([Greek: ou)de\n ga/r e)sti])." This is a curious passage, illustrating the dialectic habits of the day, and the pride felt in maintaining an answer once given.] [Footnote 9: Plato, Erastæ, 134 B-D. [Greek: ta\ me/tria ma/lista ô)phelei=n, a)lla\ mê\ ta\ polla\ mêde\ ta\ o)li/ga.]] [Side-note: No answer given. What is the best conjecture? Answer of the literary Erastes. A man must learn that which will yield to him the greatest reputation as a philosopher--as much as will enable him to talk like an intelligent critic, though not to practise.]