The aim of this book is to provide, within a short space, and primarily for the general reader, an account of the heresies of the Middle Ages and of the attitude of the Church towards them. The book is, therefore, a brief essay in the history not only of dogma, but, inasmuch as it is concerned with the repression of heresy by means of the Inquisition, of judicature also. The ground covered is the terrain of H. C. Lea’s immense work, ‘A History of the Inquisition of the Middle Ages’; but that was published more than thirty years ago, and since then much has been written, though not indeed much in English, on the mediæval Inquisition and cognate subjects. As the present work has been undertaken in the light of some of these more recent investigations, it is hoped that it may be of utility to rather closer students, as well as to the general reader, as a review of the subject suggested by the writings of Lea’s successors, both partizans and critics. At the same time this book does not profess to be a history, even the briefest, of the mediæval Inquisition. Its main concern is with doctrine, and for that reason chapters on Averrhoïsm and on Wyclifitism and Husitism have been included, though they have little bearing on the Inquisition.
The entire subject, on both its sides, is complex and highly controversial. Probably no conceivable treatment of it could commend itself to all tastes, be accepted as impartial by the adherents of all types of religious belief. It can, however, at least be claimed that this work was begun with no other object in view than honest enquiry, with no desire whatever to demonstrate a preconceived thesis or draw attention to a particular aspect of truth. The conclusion arrived at in these pages is, that the traditional ultra-Protestant conception of ecclesiastical intolerance forcing a policy of persecution on an unwilling or indifferent laity in the Middle Ages is unhistorical, while, on the other hand, some recent Catholic apologists, in seeking to exculpate the Church, have tended to underestimate the power and influence of the Church, and to read into the Middle Ages a humanitarianism which did not actually then exist. Heresy was persecuted because it was regarded as dangerous to society, and intolerance was therefore the reflection, not only of the ecclesiastical authority, but of public opinion. On the other hand, clerical instruction had a large formative influence in the creation of public opinion...
