All unhappiness depends upon some kind of disintegration or lack of integration; there is disintegration within the self through lack of coordination between the conscious and the unconscious mind; there is lack of integration between the self and society where the two are not knit together by the force of objective interests and affections. The happy man is the man who does not suffer from either of these failures of unity, whose personality is neither divided against itself nor pitted against the world.
Source: The Conquest of Happiness, 1930, chap. 17：The happy man
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