Denise Levertov's Collected Earlier Poems 1940-1960 brings under one cover the first published works of a poet who, though born and raised in Great Britain, has long held a distinctive place in postwar American letters. Initiating a major literary undertaking, the volume includes a group of hitherto ungathered poems, selections from Ms. Levertov's earliest book, The Double Image (1946), published in London, and her three following collections in their...