Moreover, in the scenes of which we are the actors and witnesses while we sleep, it constantly happens that one of our contemporaries has a rôle as well as ourselves: we think we see and hear him in the same place where we see ourselves. According to the animists, the primitive would explain this by imagining that his double was visited by or met with those of certain of his companions. But it would be enough that on awakening he question them, to find that their experiences do not coincide with his. During this same time, they too have had dreams, but wholly different ones. They have not seen themselves participating in the same scene; they believe that they have visited wholly different places. Since such contradictions should be the rule in these cases, why should they not lead men to believe that there had probably been an error, that they had merely imagined it, that they had been duped by illusions? This blind credulity which is attributed to the primitive is really too simple. It is not true that he must objectify all his sensations. He cannot live long without perceiving that even when awake his senses sometimes deceive him. Then why should he believe them more infallible at night than during the day? Thus we find that there are many reasons opposing the theory that he takes his dreams for the reality and interprets them by means of a double of himself.
But more than that, even if every dream were well explained by the hypothesis of a double, and could not be explained otherwise, it would remain a question why men have attempted to explain them. Dreams undoubtedly constitute the matter of a possible problem. But we pass by problems every day which we do not raise, and of which we have no suspicion until some circumstance makes us feel the necessity of raising them. Even when the taste for pure speculation is aroused, reflection is far from raising all the problems to which it could eventually apply itself; only those attract it which present a particular interest. Especially, when it is a question of facts which always take place in the same manner, habit easily numbs curiosity, and we do not even dream of questioning them. To shake off this torpor, it is necessary that practical exigencies, or at least a very pressing theoretical interest, stimulate our attention and turn it in this direction. That is why, at every moment of history, there have been so many things that we have not tried to understand, without even being conscious of our renunciation. Up until very recent times, it was believed that the sun was only a few feet in diameter. There is something incomprehensible in the statement that a luminous disc of such slight dimensions could illuminate the world: yet for centuries men never thought of resolving this contradiction. The fact of heredity has been known for a long time, but it is very recently that the attempt has been made to formulate its theory. Certain beliefs were even admitted which rendered it wholly unintelligible: thus in many Australian societies of which we shall have occasion to speak, the child is not physiologically the offspring of its parents.[108] This intellectual laziness is necessarily at its maximum among the primitive peoples. These weak beings, who have so much trouble in maintaining life against all the forces which assail it, have no means for supporting any luxury in the way of speculation. They do not reflect except when they are driven to it. Now it is difficult to see what could have led them to make dreams the theme of their meditations. What does the dream amount to in our lives? How little is the place it holds, especially because of the very vague impressions it leaves in the memory, and of the rapidity with which it is effaced from remembrance, and consequently, how surprising it is that a man of so rudimentary an intelligence should have expended such efforts to find its explanation! Of the two existences which he successively leads, that of the day and that of the night, it is the first which should interest him the most. Is it not strange that the second should have so captivated his attention that he made it the basis of a whole system of complicated ideas destined to have so profound an influence upon his thought and conduct?