A set of mental images that generally have no basis in reality.
A fantasy is inspired by imagination characterized by mental images that do not necessarily have any relationship to reality. In psychoanalysis, fantasy is regarded as a defense mechanism. For example, after being reprimanded by a supervisor, a worker may fantasize about taking over the company and firing the supervisor. Similarly, a child may fantasize about running away from home in retaliation against her parents for punishing her.
Vivid fantasies are often a part of childhood, diminishing as a child grows older. In the majority of individuals, fantasy is not a cause for concern; as long as the fantasizer is aware that the fantasy is not real, the formation of these mental images may be considered normal. When the line between fantasy and reality becomes blurred, however, it is possible that some form of mental illness is present. When the individual regards his fantasy as reality, it has become an hallucination. In such situations, the hallucination may be a symptom of schizophrenia, and professional evaluation by a psychologist or psychiatrist is required.
Klinger, Eric. Daydreaming: Using Waking Fantasy and Imagery for Self-Knowledge and Creativity. Los Angeles, CA: J. P. Tarcher, 1990.
"What Your Fantasies Reveal About You." American Health (April 1995): 68+.