This started as a little game-theoretic protocol I invented for asking embarrassing questions and morphed into what I think is an elegant way to make privacy and full honesty fully compatible.
Suppose I have a question for you but I worry it’s something too private or embarrassing for you to want to answer. If you say “no comment” that’s baaasically an affirmation, so I can’t really ask without invading your privacy. (This is assuming lying is off the table, of course.)
If you’re very Slytherin — but still fully honest — you’d anticipate this kind of question and habitually answer “no comment” when the real answer is a simple non-embarrassing no. People should eventually learn that “no comment” genuinely is not in fact a dead giveaway for “yes but I’m embarrassed to say so”. So it might not be a bad personal policy: If you’re asked a question where one hypothetical answer would be embarrassing to admit, always say “no comment” no matter what the actual answer.
Ok, but say you’re not that Slytherin. Here’s how I can still ask the question:
“Is it either the case that the answer to this question, _____, is no OR it’s yes but you’d prefer me to not know it’s yes?”
If I promise not to ask followup questions then we’re set. You can either say “no, it’s both true and I don’t mind you knowing” or “yes” which leaves me just as in the dark as before I asked it.
But that’s just in theory. In practice, a normal human answerer for whom the answer was no would be inclined to say “forget all that, your conjecture is just wrong!”. So when you carefully parse the disjunction and give the answer that leaves me in the dark, that’s evidence that the answer is yes. Because why do the work to keep me in the dark if you have nothing to hide??
In other words, information has still leaked. It would only work if you can restrict the possible answers to yes or no. Maybe by turning the convoluted disjunctive question into a multiple-choice one, like so (using the the old-fashioned example of asking someone if they’re gay):
[ ] I’m either not gay or I am and don’t want to come out of the closet
[ ] Guilty as charged
But that’s not exactly a guarantee. Even if they’re gay, you have to eliminate the counterfactual where the straight version of them ignores the checkboxes and says “What?? I’m super straight.”
To drive the point home that information is still leaking, imagine the person needs to stay in the closet at all costs. That means they have to perfectly simulate a straight person. And a straight person might ignore the checkboxes and just say “dude I’m super straight”. In which case you’re forcing the person, if they’re in fact gay, to lie to stay fully in the closet.
Unless they’ve established the personal “no comment” policy!
So that’s why that’s my personal policy and why I answer all hypothetically embarrassing questions — not just actually embarrassing ones — with “dreev.es/nocomment” which points you to this little essay and hopefully convinces you that this is not evidence in either direction about what my real answer is.
Now you’re probably thinking I must have an awful lot to hide that I went to the trouble to come up with all this. No comment.
That’s actually the whole goal! I’m just anticipating that I could someday be asked a question that I can’t answer due to privacy constraints or even that I just would prefer not to answer. That’s rare for me but in principle it’s nice to be totally honest without giving anyone and everyone the ability to extract private information from me at will.
If it’s privacy constraints involving other people you can normally just say so and that works fine. But maybe the privacy constraints are severe enough that it’s safer to follow the first rule of keeping a secret: not revealing there exists a secret. By having established this “no comment” policy ahead of time, I can — both fully honestly and without it being any kind of giveaway — answer “no comment” to any such questions in the future.
See also my collection of truth vignettes.