This book, by Darwins most celebrated modern biographers, gives a completely new explanation of how he came to his shattering theories about human origins. Until now, Desmond and Moore argue, the source of the moral fire which gives such intensity and urgency to Darwins ideas has gone unnoticed. By examining minutely Darwins manuscripts and correspondence (published and unpublished) and covert notebooks, where many of the clues lie, they show that the key to unlocking the mystery of how such an ostensibly conservative man could hold views which his contemporaries considered both radical and bestial, lay in his utter detestation of slavery. Darwins Sacred Cause will be one of the major contributions to the worldwide Darwin anniversary celebrations in 2009.