People overturn the fundamental principles established by Nature, when they divorce expediency from moral rectitude.
 Marcus Tullius Cicero, On Duties (44 BC). copy citation

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

Context

“you will say, "it was foolish of him not only not to advocate the exchange of prisoners but even to plead against such action!" How was it foolish? Was it so, even if his policy was for the good of the state? Nay; can what is inexpedient for the state be expedient for any individual citizen? XXVIII. People overturn the fundamental principles established by Nature, when they divorce expediency from moral rectitude. For we all seek to obtain what is to us expedient; we are irresistibly drawn toward it, and we cannot possibly be otherwise. For who is there that would turn his back upon what is to him expedient? Or rather, who is there that does not exert himself to the utmost to secure it?” source