[Noseshine]

I think there are two interpretations and @dewster probably wants to refer to only one of them:

- Knowledge that is implicitly contained in larger objects or concepts, but there is no need for users of those larger objects/concepts to know them. That is the vast majority of all knowledge and encompasses the things we don't even know we don't know yet. You can use a hammer on a nail without knowing anything about what is holding that hammer together or about Newton's laws.

- Explicit knowledge that you use directly. The comment is about this. Meaning, a response that lambda calculus is with us here and now implicitly falls into the first category above and is not what is meant, but why would you be better off knowing the concept directly apart from intellectual curiosity - which we can fulfill on only an insignificantly tiny fraction of the things we do.

Each time people want to add to the curriculum "you absolutely must know this!" they seem to be missing this distinction.

Given the incredibly amount of knowledge and how each and every piece of it is somehow important - but almost always only implicitly - I prefer a mindset that strives to reduce the amount I want other people to learn. Saying "no, you don't have to know/learn this" seems to be a better goal than trying to list ever more stuff. Also, the "need to know" should be much more targeted - "every programmer needs to know" is probably wrong for a lot of (most?) stuff that is labeled thus.

[dewster]

Thank you for expressing that better than I could ever do. Outside of JS sucking but being saved by extensibility, and academic interests, I've never heard a concrete reason why LC is important in a practical sense to most programmers. Can't swing a dead cat on the internet without hitting an LC article lately, and I really don't get the sudden interest and insistence that we all must learn it.

Looking into LC I was led to Curry's Paradox, the natural language version being "If this sentence is true, then Germany borders China" which (again, I'm probably just an idiot) doesn't strike me as paradox material.

This isn't some random reverse snobbery rant, I'm all for digging deep and really understanding things (I do this all the time, probably more than most engineers). But I can't see the Emperor's clothes everyone seems to be admiring, and it isn't for lack of looking.

[dllthomas]

"If this sentence is true, <false thing>" is a paradox like "this sentence is false". Implication is trivially true when the condition is false. But that would make the condition true and the sentence false.

[Noseshine]

So once again I try to interpret OP:

I think it's clear that this is a paradox in the field of logic - but only there. Few people not trained and/or thinking of "logic" (that math thing) will find this sentence paradoxical, more like "useless/meaningless". Normal people use paradox more for things like the "French paradox" (the French are health despite eating "unhealthily"). Which isn't a paradox in any logical sense, and even on a human level I myself see the paradox more in the fact that some people see a paradox at all instead of just admitting that what they think is true about nutritional science just isn't (that French phenomenon can be shown to be true in statistics, it's not just imagination).

[dllthomas]

> Normal people use paradox more for things like the "French paradox"

Maybe. Certainly, common use (and traditional use, e.g. Zeno's Paradox) include things that are not strictly a logical paradox. But I think that most people (and certainly overwhelmingly most programmers) consider "this sentence is false" to be a paradox - which is part of why I picked it as a point of reference.