Sigmund Freud (1856–1939), Austrian psychiatrist. repr. In Complete Works, vol. 21, ed. James Strachey and Anna Freud (1961). Civilization and Its Discontents, ch. 2 (1930).
Freud defined happiness as, in the strictest sense, "the (preferably sudden) satisfaction of needs which have been dammed up to a high degree." It was thus episodic by nature, since "we are so made that we can derive intense enjoyment only from a contrast and very little from a state of things."