Birds were never far from Thoreau's mind. They wing their way through his writing just as they did through his cabin on Walden Pond, summoned or dismissed at whim by his whistles. Emblematic of life, death, and nature's endless capacity for renewal, birds offer passage into the loftiest currents of Thoreau's thought. What Branka Arsic finds there is a theory of vitalism that Thoreau developed in response to his brother's death. Through grieving, Thoreau came to see life as a generative force into which everything dissolves. Death is not an annulment of life but the means of its...