Besides this, outside of these indirect reactions, the study of primitive religions has of itself an immediate interest which is of primary importance.
If it is useful to know what a certain particular religion consists in, it is still more important to know what religion in general is. This is the problem which has aroused the interest of philosophers in all times; and not without reason, for it is of interest to all humanity. Unfortunately, the method which they generally employ is purely dialectic: they confine themselves to analysing the idea which they make for themselves of religion, except as they illustrate the results of this mental analysis by examples borrowed from the religions which best realize their ideal. But even if this method ought to be abandoned, the problem remains intact, and the great service of philosophy is to have prevented its being suppressed by the disdain of scholars. Now it is possible to attack it in a different way. Since all religions can be compared to each other, and since all are species of the same class, there are necessarily many elements which are common to all. We do not mean to speak simply of the outward and visible characteristics which they all have equally, and which make it possible to give them a provisional definition from the very outset of our researches; the discovery of these apparent signs is relatively easy, for the observation which it demands does not go beneath the surface of things. But these external resemblances suppose others which are profound. At the foundation of all systems of beliefs and of all cults there ought necessarily to be a certain number of fundamental representations or conceptions and of ritual attitudes which, in spite of the diversity of forms which they have taken, have the same objective significance and fulfil the same functions everywhere. These are the permanent elements which constitute that which is permanent and human in religion; they form all the objective contents of the idea which is expressed when one speaks of _religion_ in general. How is it possible to pick them out?
Surely it is not by observing the complex religions which appear in the course of history. Every one of these is made up of such a variety of elements that it is very difficult to distinguish what is secondary from what is principal, the essential from the accessory. Suppose that the religion considered is like that of Egypt, India or the classical antiquity. It is a confused mass of many cults, varying according to the locality, the temples, the generations, the dynasties, the invasions, etc. Popular superstitions are there confused with the purest dogmas. Neither the thought nor the activity of the religion is evenly distributed among the believers; according to the men, the environment and the circumstances, the beliefs as well as the rites are thought of in different ways. Here they are priests, there they are monks, elsewhere they are laymen; there are mystics and rationalists, theologians and prophets, etc. In these conditions it is difficult to see what is common to all. In one or another of these systems it is quite possible to find the means of making a profitable study of some particular fact which is specially developed there, such as sacrifice or prophecy, monasticism or the mysteries; but how is it possible to find the common foundation of the religious life underneath the luxuriant vegetation which covers it? How is it possible to find, underneath the disputes of theology, the variations of ritual, the multiplicity of groups and the diversity of individuals, the fundamental states characteristic of religious mentality in general?