Any commentator on English verse form would be hard-pressed to ignoreW. B. Yeats, whose lyrical voice towers above all others in the first four decades of the twentieth century. Yet many critics, though applauding his genius, find a slight discomfort in the face of his rhythms, remarkable for their variation and striking in their feeling and beauty, but perhaps too erratic to explain easily. Helen Vendlers Our Secret Discipline: Yeats and Lyric Form does nothing to retract this detraction, but with great skill and expertise she explains the diversity and deviation by revealing the system behind the apparent irregularity. Offering an extended, consistent treatment of Yeatss lyric form, Vendler fills a significant gap in Yeats studies, by writing on a subject that is only touched upon piecemeal, by showing that there is more to Yeatss verse forms than imagery, strong (Irish) rhythms and blank verse, and by celebrating the poets lifelong capacity to evoke variations on prosodic forms in a way that is captivating and truly insightful.