Laura Dassow Walls's superb biography of Henry David Thoreau is the most important study of this author thus far in the twenty-first century. Beautifully written, and packed with rich detail and subtle interpretation, Walls's book teaches us much that is new about Thoreau and, furthermore, prompts us to think more deeply about and reassess this complex person and challenging writera writer whose range and mass of published and unpublished work, produced during his all too brief life (he died at age 44), is astounding. Thoreau is an inspiring radical voice for personal change and social reform, yet he is, at the same time, extremely self-centered and highly skeptical about the capacity of readers and audiences to bring about the transformations that he advocates.