It is, however, in the conception of their religion that idealisation has most plainly occurred, for it is mainly the religion of the Ninth Century, that is, of the age immediately preceding the great literary Prophets. In the documents themselves there is left to the careful reader ample indication in customs and narratives, the meaning of which has escaped the notice of the editor, that a more primitive form of religion prevailed. It would seem, as we have seen, that the name of Jehovah was unknown to them, while there are evident tokens of polytheistic belief (Gen. xxxi. 19; xxxv. 1-4). The crudity of the worship may be seen in the frequent reference to the erection of pillars and stones, which, it will be seen later, have more than a merely memorial purpose. The ease with which we find idolatry always reappearing in later history points to some hereditary tendency at work among the mass of the people. If, however, we suppose that the primitive religion was entirely heathen we shall be faced with the problem of discovering some necessary point of departure to which the higher revelation could affix itself. We may suppose, therefore, that among the ancestors of the Hebrews there was held a faith that was relatively purer than that common to the Semites, a faith which contained in itself the guarantee of the possibility of advance, if only favourable conditions arose; that "El, the Mighty One (_Shaddai_)," was worshipped, but along with the retention of customs and ideas that are to be found in some forms of demon worship, that is, with the recognition of many other great spirits, not all of whom are thought of as inimical to man; very much as we find among the North American Indians the idea of a Great Spirit, existing side by side with heathen practices and beliefs. So far our enquiry has not taken us on to very sure ground, and we must seek other methods. In the study of Comparative Religion the idea of a certain natural order of the evolution of religion predominates, but the actual origin of religion is still only a matter of speculation, as indeed it is bound to remain from the very nature of religion itself, since it is a vision of faith, rising in different ages and races through quite different processes. We propose now to take both the speculations and the assured results of the study of Comparative Religion, and using these as tests, see if they have left any traces in the evolution of the Hebrew religion or if they can guide us to its possible origins. The principles of such enquiry and application may be stated. (1) The ascertained customs and ideas of other religions, especially those of the Semites, will form a working hypothesis, and if we then find any reference to these customs or ideas in the Old Testament, it will make towards reasonable proof of a similar origin. (2) We must be careful, however, to exclude customs that are known to have been borrowed from the Canaanites, such as the practice of Baal-worship.