… [S]urely the reason we do not execute witches is that we do not believe there are such things. If we did — if we really thought that there were people going about who had sold themselves to the devil and received supernatural powers from him in return and were using these powers to kill neighbors or drive them mad or bring bad weather — surely we would all agree that if anyone deserved the death penalty, these filthy quislings did?
— C.S. Lewis, Mere Christianity (1952).
(This quote appears in the final paragraph of “Chapter 2: Some Objections” in “Book 1: Right and Wrong as a Clue to the Meaning of the Universe,” which is on p. 14 in the 2001 Harper Collins edition.)
quisling (n.): a traitor who collaborates with an enemy force occupying their country
The word is an adaption of the name of Major Vidkun Quisling, a Norwegian officer who ruled Norway from 1940 – 1945. The practice of using his name as a synonym for “traitor” comes from the widespread belief that he essentially ruled Norway on behalf of the Nazi party in Germany (1). However, some historians don’t think that’s a fair interpretation of how he governed (2).
The word “quisling” can also be used as an adjective.
(1) Oxford Living Dictionary maintained online by the Oxford University Press (2017): https://en.oxforddictionaries.com/definition/quisling
(2) Michael McLaughlin, “The Slaying of a Viking: The Epic of Vidkun Quisling,” The Barnes Review Vol. 4, No. 5 (Sep/Oct 2003). Available as a PDF here.