Lectures of Col. R. G. Ingersoll, Volume I Including His Answers to the Clergy, His Oration at His Brother's Grave, Etc., Etc.

Why I am not a Christian

What I believe

A Few Words About the Devil, and Other Biographical Sketches and Essays

A Grammar of Freethought

A handbook of Freethought

Answer to Dr. Priestley's Letters to a Philosophical Unbeliever