A continuation of A History of Freethought, Ancient and Modern, to the Period of the French Revolution, this work centres on European and American freethought in the century that saw the greatest surge of religious doubt and scepticism. At the heart of this work lies the doctrine of evolution and the birth of new sciences like anthropology, psychology, sociology and the growth of ethics without religious dogma. Together, these works should be of interest to all students of the history of ideas whatever their core interest.