This is a fascinating biography of Mark Twain (1835–1910). One of the leading historians of the history of Christianity in American culture, Gary Scott Smith analyses Twain's complicated and often contradictory attitude toward Christianity. In eight chapters, the volume reviews Twain's childhood faith and career as a journeyman printer, riverboat pilot, prospector, journalist, novelist, humourist and world traveller. Although raised a Presbyterian, Twain harboured spiritual doubts as a young man. In order to win the approval of his girlfriend Livy Langdon's family, he appeared to overcome his misgivings. After marriage, he attended church faithfully and happily spoke at churches to raise money for various missionary and philanthropic endeavours. Over the course of his forty-year friendship with the Hartford, Connecticut, Congregational pastor Joseph Twichell, he engaged in serious theological debates over traditional Christian doctrines. Like Jonathan Swift, Twain used humour to awaken people's love, pity and kindness and arouse their scorn for falsehoods and indifference to the weak, poor and oppressed. In his masterful analysis of Twain's life and thought, Smith examines Twain's changing theological views as well his attitudes toward the moral corruption and indifference of his day. More broadly, Smith's insightful study offers a window into the nature and role of Protestantism in Gilded Age American culture and its complex relationship with economic exploitation, imperialism, political greed, poverty and racism. Smith carefully analyses these themes in Twain's most popular writings. Twain mercilessly spoofed the anti-intellectualism and pious hypocrisy of pompous preachers and pretentious moralisers. Smith does an outstanding job of putting Twain's wit on full display. For instance, after reading Andrew Dixon White's A history of the warfare of science with theology in Christendom, Twain asked, ‘What is the order of theological evolution: does a person first become an idiot & then a theologian, or it is the other way about?’ (p. 98). For this reason alone, the study is a delightful read. Some scholars have labelled Twain an atheist, agnostic and heretic. Others contend that Twain attacked perversions and misrepresentations of Christianity and his views accorded with conventional beliefs of his day. In contrast, Smith argues convincingly that in the 1870s Twain likely affirmed conventional Christian views of God and other key doctrines. The deaths of his nineteenth- month-old young son and his twenty-four-year-old daughter and the precarious health of his beloved wife left Twain disillusioned with the Protestant Church and its theology. By the 1880s Twain was a tortured soul who had privately rejected the orthodox doctrine of the incarnation of Christ and substitutionary atonement, despite the grief these convictions caused his wife. Many of his published works – especially those he deemed too provocative to print while he was alive –– as well his autobiography, scathingly condemned the moral failings of the Church and traditional Christian beliefs. Crisply written and richly documented, Smith's engaging biography makes an outstanding contribution to American religious history.