It seems to me, and may seem to the reader, strange that we should need to ask the question, ‘What is poetry?’… I come, after some embarrassment, to the conclusion, that poetry is `the suggestion, by the imagination, of noble grounds for the noble emotions.’ I mean, by the noble emotions, those four principal secret passions Love, Veneration, Admiration, and Joy (this latter especially, if unselfish); and their opposites Hatred, Indignation (or Scorn), Horror, and Grief, this last, when unselfish, becoming Compassion. These passions in their various combinations constitute what is called `poetical feeling,’ when they are felt on noble grounds, that is on great and true grounds….
Farther, it is necessary to the existence of poetry that the grounds of these feelings should be furnished by the imagination. Poetical feeling, that is to say, mere noble emotion, is not poetry. It is happily inherent in all human nature deserving the name, and is found often to be purest in the least sophisticated. But the power of assembling, by the help of the imagination, such images as will excite these feelings, is the power of the poet or literally of the `Maker.’
Now this power of exciting the emotions depends, of course, on the richness of the imagination, and on its choice of those images which, in combination, will be most effective, or, for the particular work to be done, most fit….
The imagination has three totally distinct functions. It combines, and by combination creates new forms; but the secret principle of this combination has not been shown by the analysts. Again, it treats, or regards, both the simple images and its own combinations in peculiar ways; and thirdly, it penetrates, analyzes, and reaches truths by no other faculty discoverable….
A powerfully imaginative mind seizes and combines at the same instant, not only two, but all the important ideas of its poem or picture, and while it works with any one of them, it is at the same instant working with and modifying all in their relations to it, never losing sight of their bearings on each other; as the motion of a snake’s body goes through all parts at once, and its volition acts at the same instant in coils that go contrary ways….
Every great conception of poet or painter is held and treated by this faculty (imagination). Every character that is so much as touched by men like AEschylus, Homer, Dante, or Shakespeare is by them held by the heart; and every circumstance or sentence of their being, speaking, or seeming, is seized by process from within, and is referred to that inner secret spring of which the hold is never lost for an instant; so that every sentence, as it has been thought out from the heart, opens for us a way down to the heart, leads us to the centre, and then leaves us to gather what more we may; it is the open sesame of a huge, obscure, endless cave, with inexhaustible treasure of pure gold scattered in it; the wandering about and gathering the pieces may be left to any of us, all can accomplish that, but the first opening of that invisible door in the rock is of the imagination only.
The imagination must be fed constantly by external nature…. The most imaginative men always study the hardest, and are the most thirsty for new knowledge. Fancy plays like a squirrel in its circular prison, and is happy; but imagination is a pilgrim on the earth and her home is in heaven. Shut her from the fields of the celestial mounts bar her from breathing their lofty, sun-warmed air; and we may as well turn upon her the last bolt of the tower of famine, and give the keys to the keeping of the wildest surge that washes Capraja and Gorgona.