Theories of Dreams.
The earliest theories respecting dreams illustrate very clearly this perception of the remoteness of dream-life from waking experience. By the simple mind of primitive man this dream-world is regarded as similar in its nature or structure to our common world, only lying remote from this. The savage conceives that when he falls asleep, his second self leaves his familiar body and journeys forth to unfamiliar regions, where it meets the departed second selves of his dead ancestors, and so on. From this point of view, the experience of the night, though equal in reality to that of the day, is passed in a wholly disconnected region.
A second and more thoughtful view of dreams, marking a higher grade of intellectual culture, is that these visions of the night are symbolic pictures unfolded to the inner eye of the soul by some supernatural being. The dream-experience is now, in a sense, less real than it was before, since the phantasms that wear the guise of objective realities are simply images spread out to the spirit’s gaze, or the direct utterance of a divine message. Still, this mysterious contact of the mind with the supernatural is regarded as a fact, and so the dream assumes the appearance of a higher order of experience. Its one point of attachment to the experience of waking life lies in its symbolic function; for the common form which this supernatural view assumes is that the dream is a dim prevision of coming events. Artemidorus, the great authority on dream interpretation (oneirocritics) for the ancient world, actually defines a dream as “a motion or fiction of the soul in a diverse form signifying either good or evil to come;” and even a logician like Porphyry ascribes dreams to the influence of a good demon, who thereby warns us of the evils which another and bad demon is preparing for us. The same mode of viewing dreams is quite common to-day, and many who pride themselves on a certain intellectual culture, and who imagine themselves to be free from the weakness of superstition, are apt to talk of dreams as of something mysterious, if not distinctly ominous. Nor is it surprising that phenomena which at first sight look so wild and lawless, should still pass for miraculous interruptions of the natural order of events.
Yet, in spite of this obvious and impressive element of the mysterious in dream-life, the scientific impulse to illuminate the less known by the better known has long since begun to play on this obscure subject. Even in the ancient world a writer might here and there be found, like Democritus or Aristotle, who was bold enough to put forward a natural and physical explanation of dreams. But it has been the work of modern science to provide something like an approximate solution of the problem. The careful study of mental life in its intimate union with bodily operations, and the comparison of dream-combinations with other products of the imagination, normal as well as morbid, have