The Age of Reason Thomas Paine - The Age of Reason: Being an Investigation of True and Fabulous Theology, a deistic treatise written by eighteenth-century British radical and American revolutionary Thomas Paine, critiques institutionalized religion and challenges the inerrancy of the Bible. Published in three parts in 1794, 1795, and 1807, it was a bestseller in America, where it caused a short-li...