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.
What a poem means is as much what it means to others as what it means to the author; and indeed, in the course of time a poet may become merely reader in respect to his own works, forgetting his original meaning.
I take as metaphysical poetry that in which what is ordinarily apprehensible only by thought is brought within the grasp of feeling, or that in which what is ordinarily only felt is transformed into thought without ceasing to be feeling.
Therefore we value the poet. All the argument and all the wisdom is not in the encyclopedia, or the treatise on metaphysics, or the Body of Divinity, but in the sonnet or the play.