Devil's advocate comes from an old position in the Catholic Church.
You’ve probably heard the term devil’s advocate before. It refers to someone who puts forth an unpopular opinion or disputes an idea just for the sake of argument.
What you might not know is that for many years, in the Roman Catholic Church, there actually was a devil’s advocate! No, not an evil minion of Satan—a theologian known as the “Promotor Fidei,” or promotor of the faith.
This guy had a tough job. Whenever someone was nominated for canonization—that is, for sainthood—the Promotor Fidei had to argue for all the reasons the person didn’t pass muster. You could think of him as the official church skeptic. His job was to look critically at all the candidate’s alleged miracles and good works and put forth in writing every possible disqualifying shortcoming—no matter how slight.
Because the Promotor Fidei’s role was to argue against others in the church, he became known as the advocatus diaboli—the devil’s advocate.
The term shifted into popular usage, and soon anyone who was arguing an unpopular point, or just being contrarian, was said to be “playing the devil’s advocate.”
That’s your tidbit for today. If you play the devil’s advocate, you’re staking out a position you don’t necessarily agree with, either just for the sake of debate or to help someone make a really well-thought-out decision. Hardly devilish.
Cross, Frank Leslie, and Elizabeth A. Livingstone, eds. Canonization, Promotor Fidei. The Oxford Dictionary of the Christian Church, 3rd revised edition. Oxford University Press, 2005.
Dent, Susie. Devil’s advocate. Brewer’s Dictionary of Phrase and Fable, 19th ed. Chambers Harrap, 2012.
Encyclopedia Britannica, online edition. Devil’s advocate (subscription required, accessed February 9, 2017).
Oxford English Dictionary, online edition. Oxford University Press. Devil’s advocate (subscription required, accessed February 9, 2017).