The problematics of this volume are set out in the Introduction. It enquires into Gibbon's intentions, and their consequences, in publishing chapters 15 and 16 of the Decline and Fall at the end of its first volume in 1776. It raises the question, first asked by a contemporary, of how these chapters are related to his project as a historian, and goes so far as to ask whether he was as yet fully master of his intentions and the means by which he intended to pursue them. It will be a premise of this volume that he was from this point obliged to operate within a long-established context, that of ecclesiastical history, and the first six chapters consist of a study of the major historians in this field of whom he made use.

The primary question asked is what Gibbon intended by publishing two chapters on Christianity before Constantine, before proceeding to its establishment as the religion of empire. The second half of the volume is devoted to the context in which he published these chapters, what history he narrated and began to construct in them, and how his first readers understood and responded to them. This will be the history of a controversy – one which has never yet been studied in detail – and a further affirmation will be that Gibbon's reputation as an unbeliever was established before his history of the Church in the empire had been either written or published.