James Adam Commentary on Plato, Protagoras X.320A

for Pericles, the father of these young fellows here, gave them a first-rate training in the subjects for which he found teachers, but in those of which he is himself a master 320a he neither trains them personally nor commits them to another’s guidance, and so they go about grazing at will like sacred oxen, on the chance of their picking up excellence here or there for themselves. Or, if you like, there is Cleinias, the younger brother of Alcibiades here, whom this same Pericles, acting as his guardian, and fearing lie might be corrupted, I suppose, by Alcibiades, carried off from his brother and placed in Ariphron’s family to be educated: but before six months had passed he handed him back to Alcibiades, 320b at a loss what to do with him. And there are a great many others whom I could mention to you as having never succeeded, though virtuous themselves, in making anyone else better, either of their own or of other families. I therefore, Protagoras, in view of these facts, believe that virtue is not teachable: but when I hear you speak thus, I am swayed over, and suppose there is something in what you say, because I consider you to have gained experience in many things and to have learnt many, besides finding out some for yourself. So if you can demonstrate to us more explicitly that virtue is teachable, 320c do not grudge us your demonstration.
  No, Socrates, I will not grudge it you; but shall I, as an old man speaking to his juniors, put my demonstration in the form of a fable, or of a regular exposition?
  Many of the company sitting by him instantly bade him treat his subject whichever way he pleased.
  Well then, he said, I fancy the more agreeable way is for me to tell you a fable.
  There was once a time when there were gods, but no mortal creatures. 320d And when to these also came their destined time to be created, the gods moulded their forms within the earth, of a mixture made of earth and fire and all substances that are compounded with fire and earth. When they were about to bring these creatures to light, they charged Prometheus and Epimetheus to deal to each the equipment of his proper faculty. Epimetheus besought Prometheus that he might do the dealing himself; And when I have dealt, he said, you shall examine. 320e Having thus persuaded him he dealt; and in dealing he attached strength without speed; to some, while the weaker he equipped with speed; and some he armed, while devising for others, along with an unarmed condition, some different faculty for preservation.