My suggestion is simple:
- Asserts p smugly.
- Therefore, not-p.
One of the most important lessons I’ve learned from studying philosophy (and biology, for that matter) is how very little I know. In high school, I tended to think that people who disagreed with me must simply be foolish. (Not surprising — I was in high school.) Didn’t they see? The answer was so obvious. Of course p. Now that I am older and (marginally) wiser, I have come to realize that many questions of philosophy, of science, of history — they all have reasonable people on both sides of the question. The evidence just looks different to people.
Something I have noticed, though, is that people who are very smug in their knowledge are almost always wrong: people who sneer about the US funding the Taliban in the 1980s (when it didn’t exist), people who sarcastically sneer that torture obviously does not work because you cannot trust the answers you’re given, people who take the position that racism only exists in the US because people keep talking about it but that it is otherwise imaginary…it’s not just that they’re factually wrong, it’s that they’re wrong and cocky. In my experience, smugness is a pretty good heuristic for being uninformed. Being uninformed is, in turn, a pretty good heuristic for being wrong.
Therefore: I have decided that henceforth, should someone smugly assert p, I will assume not-p.