Two years ago Derek Mahon published what he called the 'selected collected' edition of his poems. It was, he said, 'in some senses, a first book, the kind of thing you put behind you before proceeding to the real business of learning and trying to create'. Understandably, he was uncertain about what this 'real business' might produce. Apart from outlawing 'impertinent rhetoricism', he was content simply to advertise himself as being 'at last in a position to begin'. Courtyards in Delft contains the first 14 results—and it's perhaps not surprising that their concerns are strikingly similar to those of his earlier work: the Troubles, the nature of human survival, the obstinate durability of 'mute phenomena', and the value of personal relationships. There is, though, a marked change in the manner of his new poems, if not in their matter. In the past, he has invariably worked best...