Another division which has done good service is that into natural and revealed religion. By natural religion has generally been understood such religion as human reason could attain to without supernatural aid. But this description does not apply to any religious system that ever prevailed largely in any country; the actual religions have all been the work of custom and age-long tradition, not of the deliberate operation of reason. Natural religion therefore is a term which is of no use to us in classification; since none of the actual religions which we have to study answers to that title. Nor is revealed religion a term we can conveniently use in such a work as this. Many religions claim to be the result of revelation, but few make it at the outset of their career. The title tells us nothing about the original character of a religion, but only that at some period in its career the claim was made for it that its origin was supernatural. If we grouped the revealed religions together we might find that the members of the group had no similarity to each other beyond the accidental circumstance that the claim of revelation had been made for them. Besides, science cannot possibly take the revealed character of any religion for granted, but must examine each such faith to see if its growth cannot be accounted for without that assumption. The term "natural" religion has, however, other meanings than that just mentioned, and some of these we may find to be of more service. It is proposed to divide religions into "natural" and "positive," or into those which have grown up and those which have been founded. The earlier religions were not due to the personal action of outstanding individuals (at least if they were, as surely they must have been in part, the individuals and their struggles are unrecorded), but were the work of unconscious growth, and were produced by forces, which, as they were at work in every part of the early world, may be called natural. These religions do not appeal to the authority of any founder, but are borne forward by custom and tradition. Some of the later systems, on the contrary, bear the names of their founders, and are said to have been introduced into the world at a certain time and place. Their beginning is fixed, and they have a body of beliefs and practices which belong to their original constitution, and possess authority for all subsequent generations of believers.