Good and evil exist only in the opinion. The wise man has only custom and usage to guide him in his acts.
 Anatole France, Thaïs (1890). copy citation

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Author Anatole France
Source Thaïs
Topic custom evil
Date 1890
Language English
Reference
Note Translated by Robert B. Douglas
Weblink http://www.gutenberg.org/files/2078/2078-h/2078-h.htm

Context

“For know that I shall make pious use of this tunic, this purse, and these sandals.” “My dear friend,” replied Nicias, “I suspect no evil, for I believe that men are equally incapable of doing evil or doing good. Good and evil exist only in the opinion. The wise man has only custom and usage to guide him in his acts. I conform with all the prejudices which prevail at Alexandria. That is why I pass for an honest man. Go, friend, and enjoy yourself.” But Paphnutius thought that it was needful to inform his host of his intention.” source