Esta citação, “A definição de insanidade é fazer a mesma coisa repetidamente e esperar resultados diferentes”, é constantemente atribuída a Albert Einstein, mas não existe registo que o mesmo alguma vez tenha dito isso.

Nem no livro, The Ultimate Quotable Einstein, Edited by Alice Calaprice, Princeton University Press, Princeton, New Jersey (2010), a citação aparece.

“Insanity is repeating the same mistakes and expecting different results.”, na sua versão inglesa tem o seu registo escrito mais antigo segundo a Wikipédia…

From the book Narcotics Anonymous, which is referred to within the Narcotics Anonymous fellowship as “the basic text”. The quotation was not in the “grey book” version of the basic text distribute­d for editing by the fellowship at large in 1980, but was in the approval version released in November, 1981. A pdf scan of the 1981 approval version can be found here, with the quote appearing on p. 11 (p. 25 of the pdf), at the end of the fourth paragraph (which begins “We have a disease; progressive, incurable and fatal”).

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