"Great poetry does not teach us anything – it changes us. Man is like a musical instrument of many strings, of which only a few are sounded by the narrow interests of his daily life; and the others, for want of use, are continually becoming tuneless and forgotten. Heroic poetry is a phantom finger swept over all the strings, arousing from man’s whole nature a song of answering harmony. It is the poetry of action, for such alone can arouse the whole nature of man. It touches all the strings – those of wonder and pity, of fear and joy. It ignores morals, for its business is not in any way to make us rules for life, but to make character. It is not, as a great English writer has said, ‘a criticism of life’, but rather a fire in the spirit, burning away what is mean and deepening what is shallow."
– W. B. Yeats, from “Irish Poets and Irish Poetry” in The Irish Fireside, October 9, 1886