We all need a Devil to play Advocate People make better arguments when they take their opponents seriously

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.

(You can see why, given the Catholic Church’s recent history, it might be important to check for skeletons in the closet of any potential saints. They weren’t so careful with their Papal knighthoods, for instance. But the office of promotor fidei no longer exists.)

Strangely — to my mind — the idea of the devil’s advocate is pretty unpopular these days. I remember using the phrase once and someone responding dismissively “Oh, a big ol’ swig of devil’s advocaat,” which was pretty funny, I have to admit. But playing devil’s advocate is now (in some circles, at least) considered a cover for racism and/or sexism, only a step removed from “I’m not a racist, but…”, and stories about it are illustrated with pictures of Milo Yiannopoulos. 

It’s a form of what I think of as intellectual inoculation. You take some weakened form of an argument and expose yourself to it, and then when you come across the real thing in the wild, you have a ready-made defence. I should really stress that, although the dislike of the devil’s advocate comes mainly from the left, intellectual inoculation is apolitical – everyone does it.

The most perfect forms are those “bingo cards” you see sometimes. I remember them especially from the great atheist-creationist wars of the 2000s, but they’re common all over the place. They give you weakened versions of the arguments you’re likely to see, so when you do bump into them, you’re prepared.

A few seconds’ Googling found me this one, a “feminist bingo” card. When someone tries to tell you that women shoulder more of the unpaid labour burden than men do (surely an undeniable truth), you can simply say “Ah ha! ‘Women do all the housework!’ Cross that off the bingo card!” Or if they say “A sexist society forces men into specific gender roles,” you can say “Oh! ‘Patriarchy hurts men too!’ Bingo!” There are plenty of these cards.

Inevitably enough there are also anti-feminist bingo cards, TERF bingo cards, trans activist bingo cards, conservative bingo cards, liberal bingo cards, alt-right bingo cards, “skeptical sexist” bingo cards, ad infinitum.

It’s a really clever idea. If someone says to you “We’re worried about opening up female-only spaces to people with male bodies,” you don’t have to think about the response to that, because you’ve already been inoculated against it. You can just say “Oooh! Men trying to invade our spaces! BINGO.” The weakened form of the argument has prepared your intellectual immune system, and you can reject it without a second’s thought.

Again: this isn’t limited to one side or other of any of the million arguments going on in our public spaces at the moment, and it’s not limited to bingo cards. Back in those atheist-creationist wars (which were the whole internet, until the race-gender wars took over), there were entire lists of The Enemy’s arguments (“the Courtier’s reply!”). You could have quite in-depth arguments going back and forth just by listing them. (“Seventeen!” “Oh, good shot. Three hundred and forty-four, section B.” “Nicely played, sir. Nicely played.”) 

Arguing against the devil’s advocate is this but in a more general form. If you encounter any counter-argument, you can simply say “oh, a big swig of the ol’ devil’s advocaat,” and ignore it. It’s like a broad-spectrum vaccine.

(As an aside: sarcasm does the same thing. If you say some obviously ridiculous argument in sarcastic form, like “Oh, I’m sure if we tear down statues of slave traders it will end racism forever/everyone will immediately forget all of history,” you inoculate people against the more reasonable non-sarcastic versions of the argument, like “if we tear down statues of slave traders, it might help reduce racism somewhat/have some impact on people’s understanding of history”.)

We are all subject to confirmation bias and cognitive dissonance; it is fun and easy to listen to arguments you agree with, but painful and hard to listen to (or be forced to take seriously!) the ones you don’t. That’s why this sort of intellectual inoculation is so popular and effective. But it’s also why we ought to be very wary of it.

A couple of counterpoints. First, there is a real thing that “don’t play devil’s advocate” is warning against. There really are people who will use it as cover to be arseholes. In that respect, it’s very like the “free speech” debate – free speech is (I think) genuinely important and worthy of protecting, not just from government censorship but from socially imposed consequences such as “cancelling”.

But inevitably, if you raise a banner of “we welcome free speech”, you’ll attract a bunch of people who genuinely care about free speech, and also a bunch of grim edgelords who just want to say horrible things to upset people. Similarly, if you say “people should be willing to listen to other people playing devil’s advocate,” then someone will use that as cover to say “but just playing devil’s advocate, what if Hitler was right?”

This is a hard problem and I don’t think there’s a simple way around it. Sometimes it’s fine to dismiss arguments; sometimes people are abusing principles of free speech or debate. But in general, the problem we have with The Discourse isn’t that we are too willing to take other people’s arguments seriously, or that we lack ways of ignoring or dismissing them. The principle of charity is not in danger of being worn out through overuse. I think we can afford to err on the side of caution on this one.

Second, there’s a difference between getting Christopher Hitchens in to argue against the canonisation of Mother Teresa, and someone popping up unasked in your mentions when you thought you were having a private conversation. But again, it’s not an easy problem to solve. Public arguments should be subject to public discussion, and (online, at least) the distinction between “private conversation” and “public argument” is increasingly fuzzy.

I don’t want to overstate this, and say that we’ll be unable to progress as a society or understand each other’s positions if we ban devil’s-advocating. But people stress-testing your beliefs will improve them; God knows it helps me when people point out my latest idiocy or non-sequitur. 

It also has real-life consequences. I write about superforecasting fairly often, so forgive me for returning to the topic. Essentially superforecasters are people who do well at predicting the future, when asked to make stark, falsifiable, time-limited predictions: “Will there be more than 200,000 confirmed cases in the state of Georgia by the 16th of May 2020?”, that sort of thing. And a recent Time article points out that “superforecasters” have done significantly better than experts – epidemiologists, virologists – at predicting the spread of Covid-19. 

So while back in April it appeared that superforecasters were outperforming the experts on coronavirus predictions, now there’s much more evidence to support that idea. The two superforecasters I spoke to about it have outscored the domain experts, on average, over 20 predictions.

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.

Or, of course, like the Catholic Church putting a prospective saint to the test.

In forecasting, we can see that process at work. The people who do best at predicting the future are the ones who are most open to hearing opposing arguments. If we remove the devil’s advocate from our thinking altogether, we literally become slightly dumber. Sometimes the statue crying tears of blood is a fake; we need the advocatus diaboli to sort the real miracles from the frauds.

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Tom Chivers is a science writer. His second book, How to Read Numbers, is out now.

TomChivers