When the United States was new, a lapsed minister named Elihu Palmer shared with his fellow Americans the radical idea that virtue required no religious foundation. A better source for morality, he said, could be found in the natural world. For this, his Christian critics denounced him as a heretic whose ideas endangered the country.

One of the most infamous American freethinkers in his day, Elihu Palmer has been largely forgotten. No cache of his personal papers exists, and his book has been long out of print. Yet his story merits telling, Kirsten Fischer argues, and not only for the dramatic account of a man who lost his eyesight before the age of 30 and still became a book author, newspaper editor, and itinerant public speaker.

Palmer's "heresy" tested the nation's recently proclaimed commitment to freedom of religion and of speech. Fischer reveals that Palmer engaged in person and in print with an array of freethinkers - some famous, others now obscure. This first comprehensive biography of Palmer draws on extensive archival research to tell the life story of a freethinker who was at the heart of the new nation's protracted contest over religious freedom and free speech - a debate that continues to resonate today.