Louise Gluck says in one of her essays that every end of a book is for her a "conscious diagnostic act, a swearing off" in which she discerns the themes, habits, and preoccupations of the previous volume to define the tasks of the next. The First Four Books of Poems shows this poet in the conscious evolution she describes, marking time in changes. Readers will hear specifics of sequence: where the ferocious tension of her first book, Firstborn, moves towards the more finely-spun lyricism of her second, The House on Marshland. They will also discover how the charged nouns of that book acquire more intimate weight to become the icons in her third, Descending Figure, and then rise to an archetypal mythic scale in The Triumph of Achilles. These poems are as various as the force of Gluck's intelligence is constant. In another essay, she cautions, "the deft skirting of despair is a life lived on the surface, intimidated by depth, a life that refuses to be used by time, which it tries instead to dominate or evade." The First Four Books of Poems attests to how truly Gluck has tested and proven the validity of her own warning. The fierce, austerely beautiful voice that has become Gluck's trademark speaks in these poems of a life lived in unflinching awareness. Always she is moving in and around the achingly real, writing poems adamant in their accuracy and depth. Their progression is proof of her commitment to change; with her first four books of poetry collected in a single volume, Louise Gluck shows herself happily "used by time."