Gradually the child’s experience becomes more extensive and begins to exert upon the multitude of original beliefs an influence which sometimes continues all through life, although ultimately the progress becomes very slow. Experience steadily encroaches upon the realm of belief, driving it from ground which it previously occupied. It also gives additional authority to belief, enabling it to hold more firmly that to which previously it possessed but a doubtful title. Much that contradicts frequent experiences is taken out of the realm of belief and called a fairy tale or a story. Trees with golden apples? There is no such thing, the real apples assert--we are all mellow and meaty, not hard as gold. A Santa Claus who distributes gifts to all the children everywhere at the same time? Impossible, says everyday experience. He who is here cannot also be yonder and in a thousand other places. On the other hand, experience gives strength to the child’s belief. Single matters of belief are connected mutually and with the absolute basis of all knowledge, the sensory perceptions of the present. When I am obliged to think, however briefly and vaguely, that as really as I now see this paper and perceive the words printed on it, I was at that particular time, previous to those and those events of the meantime, at a certain place witnessing a certain act, my belief in the reality of this event is unshakable. Whatever can be connected in this manner with this fixed point, is itself fixed, placed beyond doubt. Why can I believe my dreams while I am dreaming them, but not after waking up? Because consciousness is limited during sleep. There are _no perceptions_ with their normal vividness, permanence, and distinctness, with which the dream may be compared as to its reality. There are but _few other ideas_ accompanied by a vivid idea of reality, with which the dream may be compared. The dream has therefore the _maximum of reality_ of all mental states present at that time in the mind. This is meant when we _believe_ our dreams while we dream them. In a dream it may seem real to be shot toward the moon in an immense shell in company with other people, as in Jules Verne’s story. But in waking life this thought is altogether devoid of reality. In comparison with the reality of my present experience and of my ideas of the limits of engineering, of the low temperature of interstellar space, and so on, that thought of a journey in a shell immediately makes me conscious of the vivid idea of unreality. I cannot believe that story.