From Carl Sagan's "Billions and Billions"
Chapter 16 The Rules of the Game:
MORALITY IS LINKED WITH SELF-CONTROL
Cicero, De Officiis, I, 5 :
Everything morally right derives from one of four sources: it concerns either full perception or intelligent development of what is true; or the preservation of organized society, where every man is rendered his due and all obligations are faithfully discharged; or the greatness and strength of a noble, invincible spirit; or order and moderation in everything said and done, whereby there is temperance and self-control.
It's in that chapter he discusses about the Golden Rule: Do unto others as you would have them do unto you.
And the Silver Rule: Do not do unto others what you would not have them do unto you.
Almost no one follows the Golden Rule. Even Confucius knew about it. If we repay evil with kindness, how do we repay kindness?
But the Silver Rule!! Luther King and Gandhi counseled oppressed people not to repay violence with violence but not to be compliant and obedient either.
Carl Sagan wrote the book "Billions and Billions" shortly before is death.
Raoul