This chapter endeavours to draw together the changes identified in previous chapters, placing them in a wider context and making some suggestions about their longer-term significance.

First, the manuals themselves. Gui wrote one of the first inquisition manuals with a distinct authorial voice, but he also followed earlier tradition by using predominantly the materials available to, or produced by, the Toulouse inquisition to put together the Practica. Gui may well have written it because of the changing inquisitorial landscape, with several new sects coming to the inquisitors' attention. It is an insider's book; it would have been of little use to someone with no previous understanding of the inquisitorial process. It sets out no theoretical underpinnings for the inquisition; inquisitio heretice pravitatis is a given, a task to which inquisitors are appointed by their superiors and the pope. Ugolini and the anonymous De officio are academic legal works, text-books produced de novo, limited to drawing together the law on the inquisitorial process. They follow the logic of academic works and to non-practitioners they present an easily accessible route to understanding the law on inquisition. Eymerich's novelty was to write the first manual to fix the role of the inquisition within the overall context of the Church as well as to describe heresy in essentially Thomist terms and provide advice on the investigation and resolution of cases. Like Gui, he described inquisitorial practice in considerable detail and in a highly systematic way. He was also a polemical writer, with as strong an authorial voice as Gui. But while Gui offered humane and practical advice on getting the inquisition's work done, Eymerich proposed a vision for the inquisition's role in the Church, changed the nature of some heretical offences and pushed out the boundary of the inquisition's activities. His manual was academic but also accessible to an outside audience, and that accessibility was in the end probably the reason why it proved so influential.

The relationship with the secular power was integral to the work of all inquisitors, and each relationship was defined by particular local circumstances. Our sources offer insight into how this relationship worked.