Auden liked systems. He liked to categorise and pigeonhole, but invariably with the awareness that all systems and categories only work on their own terms, that the systematiser is implicated in his creations, that consciousness, while freeing us to explain ourselves to ourselves and to each other, also imprisons us in the explanations we have framed. There can be no one to stand outside and watch (except God). Hence the provisionality, audible in all his poetry if carefully listened to, of the various systems of belief he entertained one after the other, Freudian, Marxist, liberal humanist, even and finally Christian - although this last came to seem to Auden the one that gave him the most room to manoeuvre. Such freedom within restraint characterises also, and especially, Auden's attitude to poetry. Poetic form may be arbitrary, but within its limits and limitations it permits, or rather induces, quest and discovery, although the object of discovery, especially for the Christian Auden, is always out of reach.