The Dialogues ask if belief in God can be inferred from the nature of the universe or whether it is even consistent with what we know about the universe. The Natural History of Religion investigates the origins of belief, and follows its development from harmless polytheism to dogmatic monotheism. Together they constitute the most formidable attack upon the rationality of religious belief ever mounted by a philosopher.

This edition also includes Section XI of The Enquiry Concerning Human Understanding and a letter concerning the Dialogues , as well as particularly helpful critical apparatus and abstracts of the main texts, enabling the reader to locate or relocate key topics.