Recent Thoreau scholarship has concentrated on Thoreau as prescient forest ecologist; McKibben - author of the End of Nature and one of our best-read social and environmental critics - places him firmly back in his role as cultural and spiritual seer. McKibben identifies two questions asked by Thoreau as central to a late-twentieth-century reading of Walden: "How much is enough?" and "How do I know what I want?" Questions, McKibben reminds us, that must come to dominate the end of the twentieth century if we are to live well into the twenty-first. McKibben's relevant and lively introduction and annotations to the 1854 edition make us see Walden as, among other things, a way to think about how we use our time, how we spend our money - how to live essential lives,