Whitehead's magnum opus is as important as it is difficult. It is the only work in which his metaphysical ideas are stated systematically and completely, and his metaphysics are the heart of his philosophical system as a whole. Sherburne has rearranged the text in a way designed to lead the student logically and coherently through the intricacies of the system without losing the vigor of Whitehead's often brilliant prose. "The Key renders Process and Reality pedagogically accessible for the first time."—Journal of Religion