This book provides the only detailed, systematic reconsideration of the neglected nineteenth-century positivist Auguste Comte currently available. Apart from offering an accurate account of what Comte actually wrote, the book argues that Comte’s positivism has never had greater contemporary relevance than now. Providing a lucid exposition of Comte and informed by considerable new scholarship on his work, this book will be valuable to philosophers, especially philosophers of science, a wide range of intellectual historians, and to historians of science and psychology.