I think most of us are familiar with the common semantic stopsigns like "God", "just because", and "it's a tradition." However, I've recently been noticing more interesting ones that I haven't really seen discussed on LW. (Or it's also likely that I missed those discussion.)

The first one is "humans are stupid." I notice this one very often, in particular in LW and other rationalist communities. The obvious problem here is that humans are not that stupid. Often what might seem like sheer stupidity was caused by a rather reasonable chain of actions and events. And even if a person or a group of people is being stupid, it's very interesting to chase down the cause. That's how you end up discovering biases from scratch or finding a great opportunity.

The second semantic stopsign is "should." Hat tip to Michael Vassar for bringing this one up. If you and I have a discussing about how I eat too much chocolate, and I say, "You are right, I should eat less chocolate," the conversation will basically end there. But 99 times out of a 100 nothing will actually come out of it. I try to taboo the word "should" from my vocabulary, so instead I will say something like, "You are right, I will not purchase any chocolate this month." This is a concrete actionable statement.

What other semantic stopsigns have you noticed in yourself and others?

I used the word "cut" in the title to mean the Prolog operator "cut", an operator which halts the evaluation of a statement in predicate logic.

Fiction writers often complain, "I keep procrastinating from writing," and, "Nobody reads what I write."  These complaints are usually the result of shoulds stopping them from thinking about their wants.

I've never heard anyone say, "I keep putting off playing baseball," or, "I keep putting off eating ice cream."  People who keep putting off writing don't want to write, they want to have written.  If you have to try to write more often than you have to try not to write, you've probably told yourself that you should write in order to attain some reward.  There's nothing wrong with that, but writers who complain that they keep putting off writing are often writing things with little potential payoff, like fan-fiction.  They don't stop and think how to improve the payoff that they want, because they get stuck on the should that they've cached in their heads.

I've repeatedly tried to help writers who complain that not enough people read what they write.  I explain that if you want to be read by a lot of people, you need to write something that a lot of people want to read.  This seems obvious to me, but I'm always immediately attacked by indignant writers saying that they want to write great fiction, and that one should write only to please oneself in order to write great fiction.  Sometimes these are the same people who complained that they want more people to read what they write.

Why does their desire to write great fiction take complete precedence over their desire to have readers?  Because they have cached that desire as a should.  (They haven't cached a should for their goal to get more readers because that goal arose much later, after they had already learned to write well and discovered, to their horror, that just writing well doesn't bring you readers.)  For a moral agent, shoulds trump wants, by definition.

I've explained before that I don't think there is any deep difference between wants and shoulds.  The English language doesn't pretend there is; we say "I should do X" both to mean "I have a moral obligation to do X" and "I need to do X to satisfy my goals."  The problem is that most people think there is a difference, and that shoulds are more important.  They have a want, they figure out what they need to do to satisfy it, they think aloud to themselves that they should do it, and boom, they have lexically convinced themselves that they have a moral obligation to do it.