Originally published in 1984. Paul Henri Thiery, Baron d'Holbach (1723-1789), was the center of the radical wing of the philosophers. Holbach wrote, translated, edited, and issued a stream of books and pamphlets, often under other names, that has made him the despair of bibliographers but has connected his name, by innuendo, gossip, and association, with most of what was written in defeense of atheistic materialism in late eighteenth-century France.

Holbach is best known for The System of Nature (1770) and deservedly, since it is a clear exposition of his main ideas. His initial position determines all the rest of his argument: 'There is not, there can be nothing out of that Nature which includes all beings.' Conceiving of nature as strictly limited to matter and motion, both of which have always existed, he flatly denies that there is any such thing as spirit or supernatural.

This is the third of three volumes.