This article argues that Archibald Campbell's Necessity of Revelation (1739) can be viewed as the first application of the 'science of human nature', a characteristic branch of the Scottish Enlightenment, to the study of religious belief. Adopting Baconian and Newtonian methodological principles, Campbell set hypotheses, collected historical data, and inferred conclusions about the capabilities of human nature to come to fundamental religious ideas without the aid of revelation. He did so not only to reject the 'deist' position on the powers of unassisted human reason, associated with Matthew Tindal's Christianity as Old as the Creation (1730), but also to refute Campbell's conservative critics within the Church of Scotland who had earlier tried him for heresy. Campbell's example is that of a university professor using the experimental study of religion to defeat both radical freethinking and Calvinist orthodoxy. His work is another instance of the complicated relationship between science and religion within eighteenth-century Scotland.
