I was disappointed, recently, by a debate at The SoHo Forum about the evidence for health benefits of veganism. In particular, one of the people debating constantly complained about the wording of the proposition (which he agreed to beforehand). In his closing statement, he broke his promise to Gene Epstein, the moderator, and decided to guilt people about the environmental effects of meat consumption. He specifically agreed not to bring that up in the health debate, well before the debate was finalized. It wasn't even on topic, and that he said it without giving his opponent a chance to respond (his was the final closing statement), and that's just rude.
That he ended up winning was the thing that gave me the sour taste in my mouth.
I think, for debates to be useful, you have to be able to pull the combined work and scholarship from the conflict between ideas. Sometimes that means conducting adversarial collaboration, sometimes that means simply giving researchers enough time to do extremely high quality work that utterly destroys and humiliates people who wanted to do the same for them. I imagine, almost all the time, what actually happens is between those two ends of the spectrum (or just poor scholarship). People make their case as well as they can, and without requiring consensus, they move forward. People come to their own conclusions.
But in some fields, it's more likely that those people will do slightly naughty things, like write textbooks to advance their particular view, under the guise that it is well-settled fact. Textbook decisions are sometimes made by less-than-savvy people (local school boards, for example), and so there's real public harm done by this. I think we should all expect people to be aware of their choices – a reasonable school district would approve a textbook describing evolution and greenhouse effects in the planet's atmosphere – and ideally they would be very aware of excluding ideas that might compete with those.
So when I heard this knucklehead also was bragging about having written a textbook on the subject of nutrition (despite having pretty weak views on nutritional epidemiology), I think we gained a clear insight into precisely what type of person he is. And it isn't someone we should probably ever invite to a debate.
Don't get me wrong – someone who will break their word, just to score cheap points, probably shouldn't be entrusted with anything. The attention of well-meaning debate audiences is a precious resource, damaged every time a huckster walks on-stage. It's toxic to let them. But beyond the audience-respect point, this isn't someone who can benefit even well-designed adversarial systems. There simply isn't enough time in a debate to punish someone like that for breaking rules of the debate, forget correcting all their misleading statements.
Many people can't be trusted to contribute to complex discussions. Their statements obscure more than enlighten, and unless you have the ability to really sift through everything with ideal scholarship, you should just completely ignore them. There are better sources of evidence, and if you don't use only those meeting basic standards for trust, you can't even hope for your conclusions to be random. Your opinions will be dictated by the bad actors you've let influence you.
This, by the by, is essentially the argument his opponent gave, although perhaps too politely. He misrepresented research, overstated benefits, misled the audience, and then had a pretty weak denial of his conflicts of interest. I hope the SoHo Forum Debates can get better participants.