Art would be like a dream, one of those “harmless psychoses” that Freud talks about in his New Introductory Lectures on Psychoanalysis:

The harmless dream-psychosis is the result of a withdrawal from the external world which is consciously willed and only temporary, and it disappears when relations to the external world are resumed. During the isolation of the sleeping individual an alteration in the distribution of his psychical energy also sets in; a part of the expenditure on repression, which is normally required in order to hold the unconscious down, can be saved, for if the unconscious makes use of its relative liberation for active purposes, it finds its path to motility closed and the only path open to it is the harmless one leading to hallucinatory satisfaction.

Whether we read this hallucinatory satisfaction as an example of wish fulfillment, as fantasy, or as symptom, there is still much to be learned from the analogy between art and the harmless dream-psychosis. Everything in this analogy depends on the value attributed to the withdrawal or retreat from reality. Consciously willed yet only temporary in nature, therefore part of the normal rather than of the pathological side of life or, rather, part of the pathology inherent in normality, there is a work of alteration involved in this withdrawal, the effects of which in works of art have also frequently been compared to the operations of the dream-work: displacement, condensation, figuration . . . To be sure, withdrawal is not the same as escape; retreating also treating anew. Inaction, or the closing of the path to consequent motility, can also lead to a shift in the expenditure of psychic and affective energy, away from repression and toward liberation or, vice versa, through the sheer allure of subversion back to normalization…