“Happiness is the indication that man has found the answer to the problem of human existence: the productive realization of his potentialities and thus, simultaneously, being one with the world and preserving the integrity of his self. In spending his energy productively he increases his powers, he "burns without being consumed.“”
Source: Man for Himself (1947), p.189
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Erich Fromm 119
German social psychologist and psychoanalyst 1900–1980Related quotes

"Letter from a Master Addict to Dangerous Drugs", written in 1956, first published in The British Journal of Addiction, Vol. 52, No. 2 (January 1957), p. 1 and later used as footnotes in Naked Lunch

Source: Man for Himself (1947), Ch. 4 "Problems of Humanistic Ethics"

Signs of Change (1888), Useful Work versus Useless Toil

1960s, The American Promise (1965)
Context: This was the first nation in the history of the world to be founded with a purpose. The great phrases of that purpose still sound in every American heart, North and South: "All men are created equal" — "government by consent of the governed" — "give me liberty or give me death." Well, those are not just clever words, or those are not just empty theories. In their name Americans have fought and died for two centuries, and tonight around the world they stand there as guardians of our liberty, risking their lives. Those words are a promise to every citizen that he shall share in the dignity of man. This dignity cannot be found in a man's possessions; it cannot be found in his power, or in his position. It really rests on his right to be treated as a man equal in opportunity to all others. It says that he shall share in freedom, he shall choose his leaders, educate his children, and provide for his family according to his ability and his merits as a human being.

“A man is but the product of his thoughts. What he thinks, he becomes.”
In Ethical Religion, (Madras: S. Ganesan, 1922), p. 62 http://hdl.handle.net/2027/mdp.39015002732066?urlappend=%3Bseq=66
1920s
Variant: A man is but the product of his thoughts. What he thinks, he becomes.