“Saying that something is too terrible to joke about is like saying that a disease is too terrible to try to cure it.”

"Thoughts of a Free Thinker", commencement address, Hobart and William Smith Colleges (26 May 1974)
Palm Sunday (1981)

Rates of Change (with Ty Franck as James S. A. Corey), in Meeting Infinity (2015), edited by Jonathan Strahan, and published by Solaris ISBN 978-1-84997-922-1, e-book edition

"Thieves".
Volume Two (2010)

Upon winning the 1986 Academy Award for Best Actor, (in The Color of Money), after having being nominated seven times; quoted in Tom O'Neil, "Gold Derby," http://goldderby.latimes.com/awards_goldderby/2006/09/an_oscar_finall.html, Los Angeles Times (2006-09-03)

Fiction, The Colour Out of Space (1927)

The Story Teller ISBN: 978-1-4767-2783-7 (2013)
Source: The Storyteller

§ IV
1910s, At the Feet of the Master (1911)
Context: Then as to cruelty. This is of two kinds, intentional and unintentional. Intentional cruelty is purposely to give pain to another living being; and that is the greatest of all sins — the work of a devil rather than a man. You would say that no man could do such a thing; but men have done it often, and are daily doing it now. The inquisitors did it; many religious people did it in the name of their religion. Vivisectors do it; many schoolmasters do it habitually. All these people try to excuse their brutality by saying that it is the custom; but a crime does not cease to be a crime because many commit it. Karma takes no account of custom; and the karma of cruelty is the most terrible of all.

Speaking on BBC Question Time in Lincoln https://www.youtube.com/watch?v=CTDByiSRerk, 17 January 2013. <br class="br">2013

Nus ne puet estre trop parliers
Qui sovent tel chose ne die
Qui torné li est affolie,
Car li sages dit et retrait:
Qui trop parole, il se mesfait.
Source: Perceval or Le Conte du Graal, Line 1650.