Whitehead's landmark Lowell Lectures examine three centuries of scientific development — from Galileo and Newton through Darwin and Einstein — and diagnose the philosophical assumptions that enabled and distorted that development. His central target is scientific materialism: the doctrine that nature consists entirely of matter in motion, with mind, value, and quality stripped out as secondary. Against this, Whitehead argues that experience and organism are primary and that science, properly understood, requires a richer metaphysical foundation than the mechanistic tradition has provided.