“Poets are the hierophants of an unapprehended inspiration; the mirrors of the gigantic shadows which futurity casts upon the present; the words which express what they understand not; the trumpets which sing to battle, and feel not what they inspire; the influence which is moved not, but moves. Poets are the unacknowledged legislators of the world.”

Form in Modern Poetry(1932)

Source: Guide for the Perplexed (c. 1190), Part III, Ch.29
Context: In accordance with the Sabean theories images were erected to the stars, golden images to the sun, images of silver to the moon, and they attributed the metals and the climates to the influence of the planets, saying that a certain planet is the god of a certain zone. They built temples, placed in them images, and assumed that the stars sent forth their influence upon these images, which are thereby enabled (to speak) to understand, to comprehend, to inspire human beings, and to tell them what is useful to them. They apply the same to trees which fall to the lot of these stars.

Source: Loving Each Other

Source: The Victorian Age in Literature (1913), On Algernon Charles Swinburne Ch. III: The Great Victorian Poets (p. 95)

"The Fly"
Lyrics, Achtung Baby (1991)

Dedication, st. 6
The Revolt of Islam (1817)

The Iliad and the Bible, reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 609.
Variant: It was Homer who gave laws to the artist.