What is done in a manly and courageous spirit seems becoming to a man and proper; what is done in a contrary fashion is at once immoral and improper.
 Marcus Tullius Cicero, On Duties (44 BC). copy citation

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Author Marcus Tullius Cicero
Source On Duties
Topic fashion spirit
Date 44 BC
Language English
Reference
Note Translated by Walter Miller
Weblink http://www.constitution.org/rom/de_officiis.htm

Context

“To be mistaken, on the other hand, to miss the truth, to fall into error, to be led astray — that is as improper as to be deranged and lose one's mind. And all things just are proper; all things unjust, like all things immoral, are improper. The relation of propriety to fortitude is similar. What is done in a manly and courageous spirit seems becoming to a man and proper; what is done in a contrary fashion is at once immoral and improper. {95} This propriety, therefore, of which I am speaking belongs to each division of moral rectitude; and its relation to the cardinal virtues is so close, that it is perfectly self-evident and does not require any abstruse process of reasoning to see it.” source