Plato 
Ion [PDF ebook] 

In Plato's Ion Socrates discusses with the titular character, a professional rhapsode who also lectures on Homer, the question of whether the rhapsode, a performer of poetry, gives his performance on account of his skill and knowledge or by virtue of divine possession. It is one of the shortest of Plato's dialogues.
Ion has just come from a festival of Asclepius at the city of Epidaurus, after having won first prize in the competition. Socrates engages him in discussion and Ion explains how his knowledge and skill is limited to Homer, whom he claims to understand better than anyone alive. Socrates finds this puzzling as to him it seems that Homer treats many of the same subjects as other poets like Hesiod, subjects such as war or divination, and that if someone is knowledgeable in any one of those he should be able to understand what both of these poets say. Furthermore, this man is probably not the poet, like Ion, but a specialist like a doctor, who knows better about nutrition.
Plato’s argument is supposed to be an early example of a so-called genetic fallacy since his conclusion arises from his famous lodestone (magnet) analogy. Ion, the rhapsode “dangles like a lodestone at the end of a chain of lodestones. The muse inspires the poet (Homer in Ion’s case) and the poet inspires the rhapsode.” Plato’s dialogues are themselves “examples of artistry that continue to be stageworthy;” it is a paradox that “Plato the supreme enemy of art is also the supreme artist.” Plato develops a more elaborate critique of poetry in other dialogues such as in Phaedrus 245a, Symposium 209a, Republic 398a, Laws 817 b–d. However, some researchers perceive it as a critique of unjustified belief rather than a critique of poetry in general.