An examination of Christianity's place in American life through history, from the Puritans to the administration of George W. Bush. The struggle within American Christianity, historian Wills argues, has been between the head and the heart: reason and emotion, Enlightenment and Evangelism. 18th century America saw a religious revolution--an Enlightenment culture emerged whose hallmarks were tolerance for other faiths and a belief that religion was best divorced from political institutions. Wills shows how radical a departure this was, and shows the steps by which church-state separation was enshrined in the Constitution. He shows a repeating pattern in our history: a cooling of popular religious fervor, followed by an explosion in evangelical activity--generally during times of social transformation and anxiety--and then a backlash. Wills's message is to be vigilant against the triumph of emotions over reason, but to know that the tension between them is necessary, inevitable, and unending.--From publisher description.