Two rival Erastæ — one of them literary, devoted to philosophy — the other gymnastic, hating philosophy.
As soon as Sokrates begins his interrogatories, the two youths relinquish[4] their geometrical talk, and turn to him as attentive listeners. Their approach affects his emotions hardly less than those of the Erastes. He first enquires from the athletic Erastes, What is it that these two youths are so intently engaged upon? It must surely be something very fine, to judge by the eagerness which they display? How do you mean fine (replies the athlete)? They are only prosing about astronomical matters — talking nonsense — philosophising! The literary rival, on the contrary, treats this athlete as unworthy of attention, speaks with enthusiastic admiration of philosophy, and declares that all those to whom it is repugnant are degraded specimens of humanity.
[4] The powerful sentiment of admiration ascribed to Sokrates in the presence of these beautiful youths deserves notice as a point in his character. Compare the beginning of the Charmidês and the Lysis.
Question put by Sokrates — What is philosophy? It is the perpetual accumulation of knowledge, so as to make the largest sum total.
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]
[5] Plat. Erast. 133 A-B.
[6] Plato, Erast. 133 D. τὴν φιλοσοφίαν — πολυμάθειαν.
[7] Plato, Erast. 133 E.
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?