Thus conscience does make cowards of us all;
And thus the native hue of resolution
Is sicklied o'er with the pale cast of thought. ( William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”)

[“]Twer is not a friend of mine testifying against me reluctantly and for conscience’ sake, as the prosecution would have you believe. He is a spy, performing his paid job.[”] ( Isaac Asimov, Foundation, Panther Books Ltd, published 1974, part V: The Merchant Princes, chapter 14, page 175)