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by tbrownaw 1299 days ago
>Bob: False premises lead to absurd conclusions. Therefore your demand that I agree to a "hypothetical" that we both know is false, is an attempt to pull a fast one somehow.
1 comments

Alice: have you heard of proofs by contradiction?
Alice: Assume P

Bob: P is False, there's no point

Alice: It's just a starting point for my argument

Bob: And what are you trying to go with your argument?

Alice: A proof by contradiction

Bob: A proof by contradiction assumes not(X), shows that it leads to a contradiction, therefore proving not(X) is false, and X is true. In this case assuming P to perform proof by contradiction means you will prove P is False. If that's all you want to do, there is no need as I am already in agreement that P is false.

> If that's all you want to do, there is no need as I am already in agreement that P is false.

There's a difference between believing something is true and having a proof.

Sure but this is just bob telling alice to shut the fuck up cause hes already on the same page
Alice: let's assume P==NP

Bob: that's bullshit

Alice: humor me

Bob: no

Alice: I have a proof that P!=NP

Bob: I already know that

Alice: You don't, you just guess, I have a proof

Bob: whatever, go away

Bob: Segmentation fault! (core dumped)
Plenty of people consider proof by contradiction a fast one, like all intuitionist mathematicians.
The Alices I speak to are rarely interested in this. It's usually an attempt to sneak in a plank of an argument to support some repugnant conclusion, without which plank said conclusion seems suspiciously like bigotry or a just-so story. Trickle-down economics, racial superiority, social spending, flat earthism, the divine right of kings, debt-to-GDP ratio-hacking, systemd, etc etc
This is where Bob claims to be an expert on Alice's motives (the motives that all people with her opinion secretly have), refuses to further participate in any discussions that allow Alice to contribute, and accuses anyone else who allows Alice to participate of carrying water for trickle-down economics, racial superiority, social spending, flat earthism, the divine right of kings, debt-to-GDP ratio-hacking, systemd, etc etc.

edit: not begging the question is literal racism.

Refusing to bow down to false premises is not claiming to be an expert on anyone's motives, but I sure think insisting that false premises disguised as hypotheticals are meaningful contributions to support any conclusion is wrong as hell. That's right, I said it -- defending a conclusion based on made-up facts is wrong as hell. Yes, I'm willing to die on this hill, I guess I'm just old-fashioned in my desire to discuss reality...
Do you believe there's a last prime number? Do you accept Gödel's incompleteness theorems?
Do either of those rest on "defending a conclusion based on made-up facts"? I don't think, say, proofs-by-contradiction are really comparable to the bad-faith "let's say, hypothetically" argumentative style under discussion.
> an attempt to sneak in a plank of an argument to support some repugnant conclusion

Why should that be a concern? Are you afraid you'll be forced to accept their conclusion?

>Are you afraid you'll be forced to accept their conclusion?

As per the great-great-grandparent post [0], the conclusion under discussion is based on a premise they just made up and that both speakers "know is wrong". Why should I be afraid I'll be forced to accept their conclusion? Is that a property of arguments using made-up premises? I was under the impression that such arguments were bullshit.

[0] https://news.ycombinator.com/item?id=33855071

Don't ask me, you're the one who posed the concern that they may trying to stealthily introduce a repugnant idea. I was asking why you would need to be concerned. I assumed you were suggesting it was a reason not to engage in counterfactual arguments. From your response I guess it was just a non sequeter.
Why shouldn't I ask you? You're the one who asked me whether I was afraid I'd be forced to accept some repugnant conclusion based on false premises. Who else could I ask but you?

I think I've been pretty clear in my desire to not engage in bullshit arguments in which people are allowed to make up premises; you're the one who framed it as a "concern" I might be having. It seemed like you were initially suggesting that that was unreasonable. From your response I guess it was just a non sequitur.

What's a "non sequeter", by the way?