Jokes and Their Relation to the Unconscious (Complete Psychological Works of Sigmund Freud)
Freud argues that the "joke-work" is intimately related to the "dream-work" which he had analyzed in detail in his Interpretation of Dreams, and that jokes (like all forms of humor) attest to the fundamental orderliness of the human mind.
While in this book Freud tells some good stories with his customary verve and economy, its point is wholly serious.