Human beings spend nearly all of their time in some kind of mental activity, and much of the time their activity consists not of ordered thought but of bits and snatches of inner experience: daydreams, reveries, wandering interior monologues, vivid imagery, and dreams. These desultory concoctions, sometimes unobtrusive but often moving, contribute a great deal to the style and flavor of being human. Their very humanness lends them great intrinsic interest; but beyond that, surely so prominent a set of activities cannot be functionless.
Much has been made of fantasy clinically and artistically, but little scientifically. The present book has tried to fill the gap. Taking the broad view, fantasy is defined as all mental activity, as we come to know it through subjects' verbal reports, except instrumental problem-solving and except for the processes involved in scanning stimuli. Despite the dearth of direct information about fantasy, we do have a considerable amount of knowledge about other matters directly relevant to it. Therefore, materials exist out of which to construct a first approximation to a reasonably comprehensive theory of fantasy.
The starting point for our roundup of pertinent information is a review of what is known about play and dreaming, two forms of behavior which have often been regarded theoretically to resemble fantasy in at least some central respects and about which both theory and research have been much farther advanced. The evidence confirms that play and dreaming are closely related to fantasy. Play and fantasy seem to originate in early infancy as an undifferentiated set of activities, and they develop in coherence, complexity, and realism along a parallel course until puberty, when play diminishes and fantasy reportedly increases sharply. Dreams and fantasy seem to be continuous phases of an individual's diurnal cycle, fantasy melding imperceptibly into dreaming at the onset of sleep and back again at awakening. When subjects are deprived of REM dreams, the lost dreams seem at least partially replaceable by waking accounts of the interrupted dreams or by waking hallucinations induced by drugs. The developmental continuity of fantasy and early play together with the diurnal conti