Today's post, Against Devil's Advocacy was originally published on 09 June 2008. A summary (taken from the LW wiki):

 

Playing Devil's Advocate is occasionally helpful, but much less so than it appears. Ultimately, you should only be able to create plausible arguments for things that are actually plausible.


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I didn't start thinking there might really be a chocolate cake in the asteroid belt.

You're right. The time-traveling pranksters only put a teapot there.

The best use of devil's advocacy:

How emotionally entangled are you with your point of view?

Test yourself - defend an opposing view, believing your life depends upon it.

-- Marc Stiegler, David's Sling

It seems to me that devil's advocacy is a very useful tool in situations that are actually complex, with good arguments for and against. Let's say you're going to buy a car. You can throw out some options right away - you don't have the cash for a Rolls, you don't want to buy a Jeep because you live in the city, and Ladas are junk. Some options will very obviously dominate others. But then you'll get down to a smaller set of cars that you might actually want, and you have an actual, reasonable choice between. You could very easily default to one car based on pure feel without considering other parts of it. Devil's advocacy could easily kick you out of that line of thought, into a better overall decision. "Well, I like the A-mobile, but the B-mobile is $2000 cheaper and a lot more reliable...hey, that's not such a bad idea after all". Forcing yourself to argue the merits of the contrary position, to see if any are convincing, is a good way to avoid making a decision too fast, and perhaps of helping yourself come to better conclusions.

There are limits to it, of course, just like there are to most tools. But in the right circumstance, it's a pretty reasonable thing to do.

It's not really devil's advocacy if you're unsure of the truth of the positions. It's just looking reasonably at the alternatives.

I mean it more for "I think I'm going to do X...but should I really?" situations. It's sort of an ex post version of the "think for five minutes before proposing solutions" method.

I think there is some use of devil's advocacy, at least in the sense that Michael Ruse meant when he said it is used "partly to see how far a position can be pushed before it collapses (and why the collapse),"

I'm a mathematician, so I use proof by contradiction fairly often. A typical application goes like this: I come across a statement which I believe is false, and wish to prove is false. Then I use deductive reasoning on the assumption that it is true. If I can prove something that contradicts what I already know, then I am successful. Otherwise, I update my belief about its truth value (it becomes slightly more likely that it actually is true).

What I do not do is try to make a plausible for why the statement should be true. I only do this for statements I believe might be true. So in the end, the main point of the sequence does agree with my intuition for making effective arguments.

[-]Shmi-10

On the other hand, it is really hard for me to visualize the proposition that there is no kind of mind substantially stronger than a human one. I have trouble believing that the human brain, which just barely suffices to run a technological civilization that can build a computer, is also the theoretical upper limit of effective intelligence. I cannot argue effectively for that, because I do not believe it. Or if you prefer, I do not believe it, because I cannot argue effectively for it. If you want that idea argued, find someone who really believes it.

"I do not believe it, because I cannot argue effectively for it." -- how do you know until you honestly try? Have you done your absolute best effort trying to convince your supporters that they are wrong? What if your major donor said that they would withdraw support unless they judged you to have done your best to invalidate your own arguments, would you simply refuse the money and tell them "find someone who really believes it"?

"I have trouble believing that the human brain, which just barely suffices to run a technological civilization that can build a computer, is also the theoretical upper limit of effective intelligence" -- Scott Aaronson seems to have no trouble believing something very similar. Have you gone through his argument and verified that you did come up with it independently earlier and rejected as fallacious?

What about Holden Karnofsky's arguments, did you find nothing new there? If there was something you hadn't considered before, you have probably missed an important perspective (in this case of a person who compares causes to donate to).

Have you done your absolute best effort trying to convince your supporters that they are wrong? What if your major donor said that they would withdraw support unless they judged you to have done your best to invalidate your own arguments, would you simply refuse the money and tell them "find someone who really believes it"?

No, because it's not actually a good idea to try to convince your supporters that they are wrong, especially if you don't actually think they're wrong. If someone did tell me to argue compellingly that I am wrong about something important (and assuming I decided not to attempt deceit), I would tell them that someone who actually believes that should be able to provide a more compelling argument (assuming equivalent rhetorical skills, information, etc). If they really insisted on it, I would try, but that really doesn't seem like a particularly desirable situation. If I could convince my donor to drop this weird request, I would.

On the topic of Eliezer:

Scott Aaronson seems to have no trouble believing it something very similar. Have you gone through his argument and verified that you did come up with it independently earlier and rejected as fallacious? What about Holden Karnofsky's arguments, did you find nothing new there?

I would assign a reasonably high probability that Eliezer has read Aaronson's and Karnofsky's arguments.

Additionally, on a more general level, you really don't have to have independently considered an argument prior to hearing someone else make it, in order to reject it.

"I do not believe it, because I cannot argue effectively for it." -- how do you know until you honestly try?

I think EY has better reasons than this, the most obvious being: Humans are all stupid in so many blatantly obvious ways, how could it not be possible to do better?

[-]Shmi20

I think EY has better reasons than this

Maybe, but this is the one he gives.

Yes, it is. It was sloppy.