I had no idea of the history behind “Devil’s Advocates” until now:

In the Catholic Church, when someone was being put forward for sainthood, the supporters of their canonisation would put forward the miracles and good works that they had performed in their lifetime. But someone else — the promotor fidei, promoter of the faith — would take the opposite tack. They would go through the candidate’s life, looking for things they’d done wrong; or look for evidence that the purported miracles ascribed to them were fraudulent or illusory. The promotor fidei was better known as the advocatus diaboli, or the devil’s advocate.

We all need a Devil to play Advocate by Tom Chivers

That whole post is interesting, particularly for showing how a Devil’s Advocate can be useful in making better decisions today:

One reason that superforecasters are better is that they deliberately and actively look for reasons why they might be wrong. The superforecasters interviewed in the Time piece call that “red-teaming” – that is, getting someone to look for the problems in your thinking, to see where you’ve made missteps. It’s like a software company paying white-hat hackers to try to break into your intranet, to make sure it’s secure.

We all need a Devil to play Advocate by Tom Chivers

In effect, this is why diversity of thought is so important for making good decisions: if everyone thinks alike, then you’re going to make big and terrible mistakes as an organisation.