Accepting Professor Tylor's famous minimum definition of religion as "the belief in Spiritual Beings," it is safe to say that religious belief constitutes one of the largest facts in human history. No other single subject has occupied so large a share of man's conscious life, no other subject has absorbed so much of his energy. In very early stages of culture religious belief is universal in the fullest sense of the word. It shapes all primitive institutions; it dominates life from the cradle to the grave, and creates a shadow-land beyond the grave from which the dead continue to influence the actions of the living. At a later stage of culture we see a distinction being drawn between the natural and the supernatural, the secular and the spiritual, and the beginning of an antagonism that is still with us. Of all antagonisms conceived by the brain of man this is the deepest and the most irreconcilable. Each feels that the growth of the other threatens its own supremacy, with the result that advance from either side has been contested with the greatest obstinacy and determination. And although it is true that at present the supernatural is very largely "suspect," it is still powerful. Nor is its influence confined to the lower strata of European society. It has very many representatives among the higher culture, disguised it may be under various pseudo-philosophic forms. Altogether we may say that the supernatural has never been without its "cloud of witnesses." At all times there have been individuals, or groups of individuals, who have believed themselves, and have been believed by others, to be in touch with another order of existence than that with which people are normally in contact. And apart from these specially favoured persons, the wide vogue of the belief in good and evil portents, in lucky and unlucky days, the attraction of the "occult" in fiction and in fact, all serve as evidence that belief in the supernatural is still a force with which one has to reckon.
To what causes are we to attribute the persistence of this belief in the supernatural? It is useless replying that its persistence is evidence of its truth. That clearly begs the whole question at issue. Mere social heredity will doubtless count for much in this direction. Men do not start their thinking afresh with each generation. It is based upon that of preceding generations; it follows set forms, and is generally influenced by that network of ideas and beliefs into which we are born and from which none of us ever completely escapes. Still that is hardly enough in itself to account for the persistence of supernaturalism. Assuming that originally there existed what was accepted as good evidence for the existence of a supernatural, it is hardly credible that every subsequent generation went on accepting it merely because one generation received evidence of its existence. As organs atrophy for want of exercise, so do beliefs die out in time for want of proof. Some kind of evidence must have been continually forthcoming in order to keep the belief alive and active. It is not a question of whether the evidence was good or bad. All evidence, it is important to bear in mind, is good to some one. The "facts" upon which thousands of people were put to death for witchcraft would not be considered evidence to anyone nowadays, but they were once accepted as good ground for conviction.