First published in 1930, this landmark work of philosophy remains a seminal text in the field of intellectual history. Drawing on a wide range of sources, Arthur O. Lovejoy traces the history of philosophical dualism from its ancient roots to its modern manifestations in science, religion and politics. His critique of this influential and enduring idea remains as relevant today as it was when first written. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.