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...