I think that poetry at its greatest — in Dante, Shakespeare, Donne, Milton, Blake — has one broad and essential difficulty: it is the true mode of expanding our consciousness. This it accomplishes by what I have learned to call strangeness. Owen Barfield was one of several critics to bring forth strangeness as a poetic criterion. For him, as for Walter Pater before him, the Romantic added strangeness to beauty: Wallace Stevens, a part of this tradition, has a Paterian figure cry out: “And there I found myself more truly and more strange.” Barfield says: “It must be a strangeness of meaning,” and then makes a fine distinction:
It is not correlative with wonder; for wonder is our reaction to things which we are conscious of not quite understanding, or at any rate of understanding less than we had thought. The element of strangeness in beauty has the contrary effect. It arises from contact with a different kind of consciousness from our own, different, yet not so remote that we cannot partly share it, as indeed, in such a connection, the mere word “contact” implies. Strangeness, in fact, arouses wonder when we do not understand: aesthetic imagination when we do.
Consciousness is the central theme here. As Barfield intimates, consciousness is to poetry what marble is to sculpture: the material that is being worked. Words are figurations of consciousness: metaphorical of consciousness, the poet’s words invite us to share in a strangeness. “A felt change in consciousness” is one of Barfield’s definitions of the poetic effect, and I relate this to what fascinates me most in the greatest Shakespearean characters — Falstaff, Hamlet, Iago, Lear, Cleopatra — the extraordinary changes that come about when they overhear themselves. As James Wood remarks, actually they become conscious of listening to Shakespeare, because in overhearing themselves, what they are hearing is Shakespeare. They become themselves more truly and more strange, because they are “free artists of themselves” (Hegel’s tribute to them).
The work of great poetry is to aid us to become free artists of ourselves. Even Shakespeare cannot make me into Falstaff or Hamlet, but all great poetry asks us to be possessed by it. To possess it by memory is a start, and to augment our consciousness is the goal. The art of reading poetry is an authentic training in the augmentation of consciousness, perhaps the most authentic of healthy modes.
— Harold Bloom, The Art of Reading Poetry