Socrates. It is not difficult to suggest the cause of this, my dear friend. You are evidently unable to declaim on Homer according to art and knowledge; for did your art endow you with this faculty, you would be equally capable of exerting it with regard to any other of the poets. Is not poetry, as an art or a faculty, a thing entire and one?
Ion. Assuredly.
Socrates. The same mode of consideration must be admitted with respect to all arts which are severally one and entire. Do you desire to hear what I understand by this, O Ion?
Ion. Yes, by Jupiter, Socrates, I am delighted with listening to you wise men.
Socrates. It is you who are wise, my dear Ion; you rhapsodists, actors, and the authors of the poems you recite. I, like an unprofessional and private man, can only speak the truth. Observe how common, vulgar, and level to the comprehension of any one, is the question which I now ask relative to the same consideration belonging to one entire art. Is not painting an art whole and entire?
Ion. Certainly.
Socrates. Did you ever know a person competent to judge of the paintings of Polygnotus, the son of Aglaophon, and incompetent to judge of the production of any other painter; who, on the supposition of the works of other painters being exhibited to him, was wholly at a loss, and very much inclined to go to sleep, and lost all faculty of reasoning on the subject; but when his opinion was required of Polygnotus, or any one single painter you please, awoke, paid attention to the subject, and discoursed on it with great eloquence and sagacity?
Ion. Never, by Jupiter!
Socrates. Did you ever know any one very skilful in determining the merits of Dædalus, the son of Metion, Epius, the son of Panopus, Theodorus the Samian, or any other great sculptor, who was immediately at a loss, and felt sleepy the moment any other sculptor was mentioned?
Ion. I never met with such a person certainly.