title: The metapsychology of pleasure.
mesh_terms: D000220:Adaptation, Biological; D000883:Anthropology; D005075:Biological Evolution; D002657:Child Development; D003220:Conflict, Psychological; D004328:Drive; D004532:Ego; D004644:Emotions; D049673:History, 20th Century; D006706:Homeostasis; D006801:Humans; D007060:Id; D007323:Instinct; D008960:Models, Psychological; D009042:Motivation; D010990:Pleasure-Pain Principle; D011572:Psychoanalysis / Q000266:history; D011574:Psychoanalytic Theory; D012043:Regression, Psychology