Antidosis

Again, every one of you could name many of your schoolfellows who when they were boys seemed to be the dullest among their companions, but who, growing older, outstripped them farther in intelligence and in speech than they had lagged behind them when they were boys. From this fact you can best judge what training can do; for it is evident that when they were young they all possessed such mental powers as they were born with, but as they grew to be men, these outstripped the others and changed places with them in intelligence, because their companions lived dissolutely and softly, while they gave heed to their own opportunities and to their own welfare.

But when people succeed in making progress through their own diligence alone, how can they fail to improve in a much greater degree both over themselves and over others if they put themselves under a master who is mature, of great experience, and learned not only in what has been handed down to him but in what he has discovered for himself?

But there remain still other reasons why everyone may well be astonished at the ignorance in men who venture so blindly to condemn philosophy. For, in the first place, they know that pains and industry give proficiency in all other activities and arts, yet deny that they have any such power in the training of the intellect;