A crux for a belief B is another belief C such that if I change my mind about C, that will also change my mind a lot about B.
E.g., my cruxes for “it’s raining” might include things like “I’m outdoors and can see and feel lots of water falling from the sky on me”, “I’m not dreaming”, “I don’t think aliens are trying to trick me”, and so on.
Related:
Is That Your True Rejection? (a post about noticing which of your objections to an argument would actually motivate you to change your beliefs)
How is there no blog post on this website that just introduces/explains cruxes. How. Am I missing something??
There’s already a double-crux tag which includes a brief definition of “crux”.
Yeah, but it’s silly that every description of the word “crux” for some reason needs to come bundled with “double crux”, when doublecrux is sort of a special-case that isn’t always relevant
Probably true, but my sense is that most LW uses of “crux” are in the context of “double crux” and that the term gets its name mostly from the “double crux” technique.
(Of course the term has closely related meanings completely separately from LW, but the LW usage is not quite the same as any of those.)
For the avoidance of doubt, I’m not saying it’s a bad idea for there to be something defining “crux” on its own. Just speculating as to how it came about that there isn’t one already.
I think that’s not true, and “crux” is mostly used for single cruxes.
It’s often harder to tell whether something is a double crux, and in any case “double crux” mostly only makes sense when there are exactly two people in a conversation. In a ten-person Internet forum conversation where everyone has different views, it will be a lot harder to find a claim that would update everyone about the relevant proposition—and it doesn’t especially make sense to try.
I think the concept “crux” is older than “double crux”? It’s true that a lot of people were first introduced to “crux” via the double-crux mistake (though I think this was a mistake).
It does come from doublecrux, but CFAR instructors commonly say “most of the point of the double crux session is to get the general concept of the crux into public discourse”, and indeed most of the time people don’t particularly use ‘the doublecrux technique’ but do ask questions like “what’s your crux?”
Hm, interesting. Incidentally, to me the specific question “what’s your crux?” feels off because it’s perfectly normal to believe things without having specific easily-stated cruxes for them, though of course you should in general have some sort of answer to “what would change your mind?”, and also perfectly normal to believe things and have multiple cruxes for them, whereas “what’s your crux” seems to suggest that the Right Thing is to have one crux.