Soc. Then tell me now, what I was just going to ask you, whether you think this rule holds for all the arts—that by the same art we must know the same things, and by a different art things that are not the same; but if the art is other, the things we know by it must be different also. Ion. I think it is so, Socrates. Soc. Then he who has not a particular art will be incapable of knowing aright the words or works of that art? Ion. True. Soc. Then will you or a charioteer be the better judge of whether Homer speaks well or not in the lines that you quoted? Ion. A charioteer. Soc. Because, I suppose, you are a rhapsode and not a charioteer. Ion. Yes. Soc. And the rhapsode’s art is different from the charioteer’s? Ion. Yes. Soc. Then if it is different, it is also a knowledge of different things. Ion. Yes. Soc. Now, what of the passage where Homer tells how Hecamede, Nestor’s concubine, gives the wounded Machaon a posset? His words are something like this: 
 Of Pramneian wine it was, and therein she grated cheese of goat’s milk with a grater of bronze; and thereby an onion as a relish for drink. 
 Hom. Il. 11.639-40 
 The quotation, as Plato indicates, is not accurate. Machaon was the son of Asclepius and physician to the Greeks at Troy . Nothing is known of Pramneian wine, except that it was thick and nutritious ( Athen. 1.10b ). Is it for the doctor’s or the rhapsode’s art to discern aright whether Homer speaks correctly here or not? Ion. For the doctor’s. Soc. Well now, when Homer says: 
 
 And she passed to the bottom like a plummet which, set on a horn 977) supports Aristotle’s view that the horn acted as a sheath to protect the line from being bitten through by the fish. are we to say it is for the fisherman’s or for the rhapsode’s art to decide what he means by this, and whether it is rightly or wrongly spoken? Ion. Clearly, Socrates, for the fisherman’s art. Soc. Then please observe: suppose you were questioning me and should ask: Since therefore, Socrates, you find it is for these several arts to appraise the passages of Homer that belong to each, be so good as to make out those also that are for the seer and the seer’s art, and show me the sort of passages that come under his ability to distinguish whether they are well or ill done ; observe how easily and truly I shall answer you. For he has many passages, both in the Odyssey , as for instance the words of Theoclymenus, the seer of the line of Melampus, to the suitors: