This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book draws attention to methodological challenges raised by new approaches to the study of atheism and deism. It concentrates on heterodoxy in England, but with the aim of raising issues which reverberate, albeit somewhat differently, elsewhere for example, in Europe, in the Americas and in the Pacific. It considers the understanding of miracles held by two later English deists, Thomas Chubb and Thomas Morgan, whose lives were intertwined. The book shows that the charge of atheism was central to the reception of Jeffrey Collins's work in Britain and that, contrary to older interpretations, this charge had a serious philosophical basis. It offers a revisionist interpretation of Hume's attitude to natural religion. It argues that both the deist idea that God does not intervene in the world and the idea that universal morality is rationally accessible are distinctly non-Humean.