At his death in 1882, Emerson left behind a trove of unpublished material extraordinary for its quantity and depth-hundreds upon thousands of pages of journals, letters, notebooks, and lectures that dwarf his nine books in volume and scope but were never seen during his lifetime. His most important manuscripts have gradually filtered through to the public over the course of the last hundred and twenty-five years, save one: the final product of what he himself considered to be the "chief task of his life." Here for the first time in print are the last lectures of Emerson's career, a cycle of seventeen that he delivered at Harvard University in 1871. In his last lectures, Emerson set out to gather and structure the best thoughts of a project that spanned thirty-three years and ran as a constant, though largely hidden, thread throughout his active career. The result is a vibrant fabric of thought, image, and word as startling for the boldness of its pattern as for its immediacy and relevance to the modern reader. The powers of the mind and states of consciousness, the transcendency of physical into spiritual laws, the governing influence of Ideas in the history of humankind, and the ethical duty laid upon those who recognize the Good Cause as their own-all serve as themes and elements of Emerson's portrait of a practical understanding of the -spiritual foundations of human experience and self-development.