Poetry may make us from time to time a little more aware of the deeper, unnamed feelings which form the substratum of our being, to which we rarely penetrate; for our lives are mostly a constant evasion of ourselves.
Not only every great poet, but every genuine, but lesser poet, fulfils once for all some possibility of language, and so leaves one possibility less for his successors.
I have said that poetry is the spontaneous overflow of powerful feelings: it takes its origin from emotion recollected in tranquillity: the emotion is contemplated till, by a species of reaction, the tranquillity gradually disappears, and an emotion, kindred to that which was before the subject of contemplation, is gradually produced, and does itself actually exist in the mind.
The poet's mind is in fact a receptacle for seizing and storing up numberless feelings, phrases, images, which remain there until all the particles which can unite to form a new compound are present together.
Good poetry could not have been otherwise written than it is. The first time you hear it, it sounds rather as if copied out of some invisible tablet in the Eternal mind than as if arbitrarily composed by the poet.