With the Inquisition proper, which some might call the most characteristic of all medieval institutions, I have no space to deal fully here. I shall say nothing, concerning the institution itself, which I have not already said at greater length elsewhere, especially in my recent Inquisition and Liberty. Here, it will be best to plunge straight into the heart of the subject, to picture things as they were in the golden thirteenth century, and then to explain how almost inevitably they had grown to what they were.

A distinguished Roman Catholic historian of philosophy has written: “The thirteenth century believed that it had realized a state of stable equilibrium.…Their extraordinary optimism led them to believe they had arrived at a state close to perfection.” This, behind its obvious exaggerations, is in many ways only too true; society did to a great extent accept the Church's claims to perfection, and her pitiless repression of all that opposed this claim. But, on the other hand, here is a cry which comes to us from the very days which Professor de Wulf is describing. Berthold of Regensburg is here speaking; that Franciscan whom Roger Bacon singles out as the greatest preacher of his time; the man whose influence and success became legendary; the greatest mission preacher, perhaps, of the whole Middle Ages.