(Published today in Quora)
There is a great deal of misunderstanding concerning this topic – Plato’s criticism of poetry in particular and art in general (Bertrand Russell is quite unreliable on his account of the history of Western philosophy; witty but severely flawed). Based on the evidence (Plato’s writings) it can be said that poetry is too important – it was so for Plato, a great poet himself – to leave it to the (bad) poets, and the same for music and the other art forms. There is much that could be writen about this. Importantly, the products of art are at a third remove from reality, while a manufactured object, such as a chair, is at a second remove – this concerns epistemology and ontology.
Plato admired Homer, even memorizing fragments of this great mythologer’s writings. As for music, he admitted for his Republic only two or three musical styles, which were more sober and noble than the loud and dissonant pieces that people were used to (and liked).
I would strongly recommend ‘Plato’s Defence of Poetry’, by Julius A. Elias (1984). Plato’s thrust was mainly a moral one, following on Socrates as a religious reformer: “The religious objections… stress the responsibility of poets who represent the gods and the moral order of the universe in an offensive manner. The gods indulge in all seven deadly sins with an enviable immunity… guilty conscience, venereal disease… “.
Concerning poetry, “… And if any man come to the gates of poetry without the madness of the Muses, persuaded that skill alone will make him a good poet, then shall him and his woks of sanity with him be brought to nought by the poetry of madness” (Madness=divine inspiration).
Plato – Phaedrus, 245