But primitive religions do not merely aid us in disengaging the constituent elements of religion; they also have the great advantage that they facilitate the explanation of it. Since the facts there are simpler, the relations between them are more apparent. The reasons with which men account for their acts have not yet been elaborated and denatured by studied reflection; they are nearer and more closely related to the motives which have really determined these acts. In order to understand an hallucination perfectly, and give it its most appropriate treatment, a physician must know its original point of departure. Now this event is proportionately easier to find if he can observe it near its beginnings. The longer the disease is allowed to develop, the more it evades observation; that is because all sorts of interpretations have intervened as it advanced, which tend to force the original state into the background, and across which it is frequently difficult to find the initial one. Between a systematized hallucination and the first impressions which gave it birth, the distance is often considerable. It is the same thing with religious thought. In proportion as it progresses in history, the causes which called it into existence, though remaining active, are no longer perceived, except across a vast scheme of interpretations which quite transform them. Popular mythologies and subtile theologies have done their work: they have superimposed upon the primitive sentiments others which are quite different, and which, though holding to the first, of which they are an elaborated form, only allow their true nature to appear very imperfectly. The psychological gap between the cause and the effect, between the apparent cause and the effective cause, has become more considerable and more difficult for the mind to leap. The remainder of this book will be an illustration and a verification of this remark on method. It will be seen how, in the primitive religions, the religious fact still visibly carries the mark of its origins: it would have been well-nigh impossible to infer them merely from the study of the more developed religions.
The study which we are undertaking is therefore a way of taking up again, _but under new conditions_, the old problem of the origin of religion. To be sure, if by origin we are to understand the very first beginning, the question has nothing scientific about it, and should be resolutely discarded. There was no given moment when religion began to exist, and there is consequently no need of finding a means of transporting ourselves thither in thought. Like every human institution, religion did not commence anywhere. Therefore, all speculations of this sort are justly discredited; they can only consist in subjective and arbitrary constructions which are subject to no sort of control. But the problem which we raise is quite another one. What we want to do is to find a means of discerning the ever-present causes upon which the most essential forms of religious thought and practice depend. Now for the reasons which were just set forth, these causes are proportionately more easily observable as the societies where they are observed are less complicated. That is why we try to get as near as possible to the origins.[3] It is not that we ascribe particular virtues to the lower religions. On the contrary, they are rudimentary and gross; we cannot make of them a sort of model which later religions only have to reproduce. But even their grossness makes them instructive, for they thus become convenient for experiments, as in them, the facts and their relations are easily seen. In order to discover the laws of the phenomena which he studies, the physicist tries to simplify these latter and rid them of their secondary characteristics. For that which concerns institutions, nature spontaneously makes the same sort of simplifications at the beginning of history. We merely wish to put these to profit. Undoubtedly we can only touch very elementary facts by this method. When we shall have accounted for them as far as possible, the novelties of every sort which have been produced in the course of evolution will not yet be explained. But while we do not dream of denying the importance of the problems thus raised, we think that they will profit by being treated in their turn, and that it is important to take them up only after those of which we are going to undertake the study at present.