Erudite Thomas Jefferson, wily Benjamin Franklin, rough-hewn general Ethan Allen and Thomas Young (who instigated the Boston Tea Party)—the radicals who founded America set their sights on a revolution of the mind. Derided as "infidels" and "atheists" in their time, they wanted liberation from a king but also from supernatural religion. The ideas that inspired them were largely ancient, pagan and continental: the fecund universe of Lucretius; the potent natural divinity of Spinoza.

From the meaning of "nature’s God" and "self-evident" in the Declaration of Independence to the sources of The United States’s success in science, medicine, the arts, religious tolerance and democratic governance, Matthew Stewart’s investigation surprises, challenges, enlightens and entertains as a philosophical detective story of the highest order.