The breakdown of religious uniformity was an essential precondition of Scotland's post-Restoration culture of controversy. In the four and a half decades after 1660, the country's shared religious understanding fissured, and rival confessional cultures emerged. Crucial to this process was the refusal of individuals and groups of people to conform to the established Church. As chapters 2 and 3 explain, the presbyterians' ecclesiology, and their adherence to the Covenants, led them to dissent from the episcopalian Church from 1662. Twenty-eight years later, the revolution settlement of the crown and Kirk was unacceptable to most episcopalians, and large numbers failed to conform to the re-established presbyterian Church. Among both presbyterian and episcopalian dissenters there were disagreements about the ways in which their nonconformity should be expressed, and the extent to which they should compromise with the established Church. Whereas the theme of nonconformity is implicit in much of the rest of the book, the present chapter analyses it in detail. It examines principled and practical arguments surrounding nonconformity, in the Restoration period and after the revolution. The chapter also surveys the various possible acts of nonconformity, ranging from temporary separation from a particular congregation to repudiation of the established Church as a whole. These nonconformist acts can be seen as ways in which ministers and lay people could voice their disapproval of erroneous religious policies, or of the Church's fundamental principles.