Almost the end of January, and not a single Language Log reader hasn't failed to complain about the lack of over-negation in any of this year's posts. But here's some naughtily nutty negation anyway:
"It's not that I don't doubt the sincerity of their desire to protect the talent. And believe it or not, we have the same ambition," Christian Mann, general manager of Evil Angel Productions who also serves on the porn industry's Free Speech Coalition, said last week after the council's vote. "We just don't believe their way is the best way." (Associated Press, LA mayor signs law requiring condoms in porn films, Jan. 24, 2012; widely syndicated story.)
Hmm. That's a curious lack of non-self-doubt. So does it mean Mann does in fact doubt the sincerity of "their" desire to protect the talent? I don't think so.
It turns out that the pattern is surprisingly common. Here are a bunch of web examples (from among many more, easily found) all of which appear to me to have a tad more negation than their intended truth conditions warrant:
It's not that I don't doubt Kevin is low enough to get Britney pregnant for some extra cash, it's just that I don't think he's clever enough.
It’s not that I don’t doubt that little happy crazy girl who’s smile was so big and bounced into a room is gone, it’s just completely dulled with that girl who smiles awkwardly when she’s forced to and walks with feet shuffling. It’s so bad that when I’m with her, even I doubt her capacity for depth of emotion.
It’s not that I don’t doubt color affects us profoundly. We make choices based on colour on a daily basis – what clothes will we wear? What food will we eat?
It's not that I don't doubt colloidal silver's power, as it was used for centuries to treat wounds.
It’s not that I don’t doubt some of the books are good (or impacted literature or culture at the time); it’s just that there tends to be too much hype surrounding them. War and Peace? Couldn’t even finish. Jane Austen? Not too impressed. That being said, I did enjoy A Handmaid’s Tale (I have a terrible soft spot for dystopia).
You might say that Christian Mann and all these other guys are following a principle of prophylactic over-negation:
To protect your interlocutor from something false, swaddle the offending proposition in as many layers of negativity as possible.
So the idea is that speakers who produce all these negations might be subconsciously operating on the intuition the more layers of protective negativity you wrap around a proposition, the less chance that any contaminating falsity will leak out. Now the standard approach to negation, beloved of logicians and sticklers alike, says that two negations are similar to no negations. But isn't that like saying two wrongs make a right? That using both a belt and suspenders will combine to make your pants fall down? Or that using two condoms is just like having unprotected sex? Is that not unintuitive? And do you not doubt that the principle of prophylactic over-negation is not more reasonable?