The critical writings of poets often have surprisingly little to do with their own work. This sometimes has an obvious enough cause: poets are usually poor and must take in whatever reviewing work comes their way. But there are other, more interesting reasons for this state of affairs. An artist such as T. S. Eliot seems to have seen his critical essays as a sort of elaborate smokescreen thrown up around his poetry and plays, the better to keep their magic and mystery inviolate. The famous meditations on Milton, on the metaphysical poets, and on tradition itself have little enough in the end to do with The Waste Land or Four Quartets, despite the heroic and desperate efforts of scholars to posit some connections. When Eliot wrote of the need in all healthy art to make a separation between the man who suffers and the mind which creates, he may have come as near to critical autobiography as he dared.

Not so with W. B. Yeats. Though he was, in his youth, far more dependent than Eliot on whatever reviewing came his way, he had a happy knack of using every kind of artist as a means of exploring himself. Criticism, as he practiced it, was really an overflow of his autobiography, a way of sharing the readerly experience with a wider audience. Subsequent Irish poets have written good criticism - notably Patrick Kavanagh and Seamus Heaney - but they have often been fearful of writing too much. Heaney has spoken of an artist's need to remain capable of accident and surprise, and of the consequent danger of becoming overly self-conscious in the creative process. You might, he warns, come to believe more in the critical coroner in yourself than in the person open to the unexpected.