Critical studies of religion and fiction in the eighteenth century have tended to centre either on the relationship between the major novelists and the contemporary currents of deism or latitudinarianism, or on the ways in which the novel came to rival the pamphlet and the sermon as a testing-ground for questions of morality and virtue. This article argues that the truth claims of the emerging novel might also be read in terms of theological controversy, an argument which is prompted by the explicit linking of these issues in Thomas Amory's novel, The Life of John Buncle, Esq (1756). Contemporary responses to the novel read it as a comic satire on its fervently anti-trinitarian protagonist, but they did so because the reviewers were laughing at, rather than with, Buncle. Amory, in representing a zealous, even ‘enthusiastic’ Unitarian, explored a character who was comically earnest, dogmatic in his religious toleration, and passionate in his defence of theological rationalism. But in writing a form of fiction, Amory could exploit a genre which permitted an imagining of that which might appear improbable but which can nevertheless claim to be true, and thus mediate between knowledge and faith, between reason and revelation.