"In the Systême, Holbach rejected the Cartesian mind-body dualism and attempted to explain all phenomena, physical and mental, in terms of matter in motion. He derived the moral and intellectual faculties from man's sensibility to impressions made by the external world, and saw human actions as entirely determined by pleasure and pain. He continued his direct attack on religion by attempting to show that it derived entirely from habit and custom. But the Systêm was not a negative or destructive book: Holbach rejected religion because he saw it as a wholly harmful influence, and he tried to supply a more desirable alternative."--PMM215.