John Hildebidle reintroduces us to Thoreau as natural history writer, bringing fresh insight to Walden, Cape Cod, and the later nature pieces--both published and unpublished--and the tradition of nature writing as well. Hildebidle examines Thoreau's attitude toward history and science, demonstrating that he manages to use "secondhand" material while insisting that only firsthand experience has any value. Although sharing the naturalist's eye and methods, Thoreau never rests in the role of observer and collector. Hildebidle sees Thoreau as representative of a long-standing American tendency simultaneously to reject and to use the past, and shows how, as naturalist, he brought together science and literary aims. This gracefully written analysis of Thoreau's thinking and style will well serve all readers of Thoreau and those interested in natural history as a genre.