Hitherto this thought has been applied in certain departments of inquiry, but I am of impression that its considerable and world-wide significance has been missed. Freud, in his _Traumdeutung_, insists that behind the dream, and inspiring its action and symbolism there always lurks an emotion, a desire, a wish. And Havelock Ellis (though with due caution) corroborates this. He speaks[102] of “the controlling power of emotion on dream-ideas,” and says, “the fundamental source of our dream-life may be said to be emotion.” That is, an emotion (from whatever source) arises in the mind. Vague and cloudlike at first, it presently takes form, and (if in sleep) clothes itself with the imagery of a dream, which becomes at last vivid and dramatic and _real_, to a degree which astounds us. But dream-life is only a paraphrase, so to speak, of waking life—a phase largely corresponding to the waking life of children[103] and animals; and in waking life the same thing happens. A wish or desire appears in the background of the mind; it moves forward and becomes a definite thought and a plan; then it moves forward again and becomes an action; the action creates a result; and the desire finally establishes itself or its image in the actual world. These emotions and desires and the images which sprung from them have a certain vitality and growth-power of their own. The figures in dreams move of themselves and concatenate with each other of their own accord—much as the figures do in a drama, as Coleridge long ago observed—and as the waking thoughts of all of us do, when we leave them a little to themselves and to go with loose rein. More than that; in some cases waking thoughts or passions become powerful enough to take possession of the whole man and embody themselves in his deeds—sometimes to heroic, sometimes to criminal ends. Or, taking possession of _portions_ of the man, they precipitate conflict within him. The dramatic quality of dreams is evidently due to the different figures or incidents of the dream being inspired by different qualities or experiences of the dreamer; and in the waking man the same process may lead to tragic struggles and disintegrations of personality. In hysteric patients, where the central controlling power is weak, the very thought or fear of a disease may seize upon a certain centre in the body and stimulate there all the symptoms of that disease; or a mental image may seize upon a certain portion of the brain, and break up the personality with strange new manifestations.