In psychology, fantasy is a broad range of mental experiences, mediated by the faculty of in the human brain, and marked by an expression of certain desires through vivid mental imagery. Fantasies are generally associated with scenarios that are impossible or unlikely to happen.
In everyday life, individuals often find their thoughts "pursue a series of fantasies concerning things they wish they could do or wish they had done ... fantasies of control or of sovereign choice ... daydreams." George Eman Vaillant in his study of defence mechanisms took as a central example of "an immature defence ... fantasy living in a 'Walter Mitty' dream world where you imagine you are successful and popular, instead of making real efforts to make friends and succeed at a job." Other researchers and theorists find that fantasy has beneficial elements providing "small regressions and compensatory wish fulfilments which are recuperative in effect." Research by Deirdre Barrett reports that people differ radically in the vividness, as well as frequency of fantasy, and that those who have the most elaborately developed fantasy life are often the people who make productive use of their imaginations in art, literature, or by being especially creative and innovative in more traditional professions.
According to Sigmund Freud, a fantasy is constructed around multiple, often repressed wishes, and employs disguise to mask and mark the very defensive processes by which desire is enacted. The subject's desire to maintain distance from the repressed wish and simultaneously experience it opens up a type of third person syntax allowing for multiple entry into the fantasy. Therefore, in fantasy, vision is multiplied—it becomes possible to see from more than one position at the same time, to see oneself and to see oneself seeing oneself, to divide vision and dislocate subjectivity. This radical omission of the “I” position creates space for all those processes that depend upon such a center, including not only identification but also the field and organization of vision itself. For Freud, sexuality is linked from the very beginning to an object of fantasy. However, “the object to be rediscovered is not the lost object, but its substitute by displacement; the lost object is the object of self-preservation, of hunger, and the object one seeks to re-find in sexuality is an object displaced in relation to that first object.” This initial scene of fantasy is created out of the frustrated infants' deflection away from the instinctual need for milk and nourishment towards a phantasmization of the mothers' breast, which is in close proximity to the instinctual need. Now bodily pleasure is derived from the sucking of the mother's breast itself. The mouth that was the original source of nourishment is now the mouth that takes pleasure in its own sucking. This substitution of the breast for milk and the breast for a phantasmic scene represents a further level of mediation which is increasingly psychic. The child cannot experience the pleasure of milk without the psychic re-inscription of the scene in the mind. “The finding of an object is in fact a re-finding of it.” It is in the movement and constant restaging away from the instinct that desire is constituted and mobilized.
Lacan engaged from early on with "the phantasies revealed by Melanie Klein ... the imago of the mother ... this shadow of the bad internal objects" with the Imaginary. Increasingly, however, it was Freud's idea of fantasy as a kind of "screen-memory, representing something of more importance with which it was in some way connected" that was for him of greater importance. Lacan came to believe that "the phantasy is never anything more than the screen that conceals something quite primary, something determinate in the function of repetition." Phantasies thus both link to and block off the individual's unconscious, his kernel or real core: "subject and real are to be situated on either side of the split, in the resistance of the phantasy", which thus comes close to the centre of the individual's personality and its splits and conflicts. "The subject situates himself as determined by the phantasy ... whether in the dream or in any of the more or less well-developed forms of day-dreaming;" and as a rule "a subject's fantasies are close variations on a single theme ... the 'fundamental fantasy' ... minimizing the variations in meaning which might otherwise cause a problem for desire." The goal of therapy thus became "la traversée du fantasme, the crossing over, traversal, or traversing of the fundamental fantasy." For Lacan, "The traversing of fantasy involves the subject's assumption of a new position with respect to the Other as language and the Other as desire ... a utopian moment beyond neurosis." The question he was left with was "What, then, does he who has passed through the experience ... who has traversed the radical phantasy ... become?."