The work caused immense alarm, and was condemned by the council of Arles,(285) on the ground that it assumed that Christianity was imperfect, and was to be replaced by a superior revelation developing from natural causes. It is doubtful whether the book was really intended to be sceptical. More probably it was mystical. Claiming to be founded on an apocalyptic idea,(286) it was a revival of the Chiliasm which haunted the Christians of Asia Minor in the early centuries; perhaps also it was the utterance of the spiritual yearning which marked the rise of the Franciscan order, and a protest against the worldliness of the times. It was connected too with the longings for political deliverance from the temporal dominion of the Popedom which were now beginning to be felt. In these latter aspects the idea, so far from being false, was an advance. Christianity from time to time admits a progress, but from within rather than from without; a deeper spiritual appreciation of old truths rather than a reception of new ones. The demand for progress becomes a ground for alarm only when it implies that the world has bidden farewell to Christianity, either through the mystical expectation of a Millennial reign which is to supersede it, or through the sceptical belief that our religion has only an historic value, and needs remodelling to meet the requirements of advancing civilization. If the latter was the meaning of this utterance of the Franciscan book, the idea was the germ of the modern conception of the function of Christianity in “the education of the race,” the first statement of which is usually attributed to Lessing.(287) The same century which gave birth to this _mot_, expressive of _progress in religion_, created also another which embodied the idea of the _comparative study of religions_. This phrase may have different meanings. It may signify the comparison of Christianity with ethnic creeds in its external and internal character, without sacrificing the belief that a divinely revealed element exists in it, which caused it to differ from them in kind as well as degree. Or it may mean a comparison of Christianity with other religions, as equally false with them, equally a deliberate and conscious invention of priestcraft which was the shocking view adopted by writers like Volney in the last century,(288) or else a comparison of it as equally true with them, as equally a psychological development of the religious intelligence, which is the view prevalent in many noted works on the philosophy of history in the present.(289) It was the second of these ideas, expressive of actual incredulity, which existed in the thirteenth century. It is traceable in the imputation made by Gregory IX(290) against the celebrated emperor Frederick II, that he had spoken of Moses, Christ, and Mahomet, as the three great impostors who had respectively deceived the Jews, the Christians, and the Arabs.