2009 reprint of 1854. Henry David Thoreau (1817 - 1862) is best known for his book Walden, a reflection upon simple living in natural surroundings. Thoreau's lasting contributions were his writings on natural history and philosophy, where he anticipated the methods and findings of ecology and environmental history, two sources of modern day environmentalism. His literary style interweaves close natural observation, personal experience, pointed rhetoric, symbolic meanings, and historical lore; while displaying a poetic sensibility, philosophical austerity, and "Yankee" love of practical detail. He was also deeply interested in the idea of survival in the face of hostile elements, historical change, and natural decay; at the same time imploring one to abandon waste and illusion in order to discover life's true essential needs. Walden remains to this day one of the great books of American literature.