William Blake and the Imagination in Ideas of Good and Evil by William Butler Yeats.

“He had learned from Jacob Boehme and from old alchemist writers that imagination was the first emanation of divinity, ‘the body of God,’ ‘the Divine members,’ and he drew the deduction, which they did not draw, that the imaginative arts were therefore the greatest of Divine revelations, and that the sympathy with all living things, sinful and righteous alike, which the imaginative arts awaken, is that forgiveness of sins commanded by Christ.” [via]

Consider also:

  1. “In our time we are agreed that we ‘make our souls’ out of some one of the great poets of ancient times, or out of Shelley or Wordsworth, or Goethe or Balzac, or Flaubert, or Count Tolstoy, in the books he wrote before he became a prophet and fell into a lesser order, or out of Mr. Whistler’s pictures, while we amuse ourselves, or, at best, make a poorer sort of soul, by listening to sermons or by doing or by not doing certain things.”
  2. “This philosophy kept him more simply a poet than any poet of his time, for it made him content to express every beautiful feeling that came into his head without troubling about its utility or chaining it to any utility.”
  3. “Ideas cannot be given but in their minutely appropriate words, nor can a design be made without its minutely appropriate execution.”
  4. “This letter may have been the expression of a moment’s enthusiasm, but was more probably rooted in one of those intuitions of coming technical power which every creator feels, and learns to rely upon; for all his greatest work was done, and the principles of his art were formulated, after this date. Except a word here and there, his writings hitherto had not dealt with the principles of art except remotely and by implication; but now he wrote much upon them, and not in obscure symbolic verse, but in emphatic prose, and explicit if not very poetical rhyme.”
  5. “The technique of Blake was imperfect, incomplete, as is the technique of well-nigh all artists who have striven to bring fires from remote summits; but where his imagination is perfect and complete, his technique has a like perfection, a like completeness.”