6 ms·

Alice: have you heard of proofs by contradiction?

by ajuc 4y ago

arthurcolle 4y ago
Bob: Segmentation fault! (core dumped)
revolvingocelot 4y ago
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
- pessimizer 4y ago
  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.
  - revolvingocelot 4y ago
    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...
    - ajuc 4y ago
      Do you believe there's a last prime number? Do you accept Gödel's incompleteness theorems?
      - revolvingocelot 4y ago
        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.
- seti0Cha 4y ago
  > 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?
  - revolvingocelot 4y ago
    >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 https://news.ycombinator.com/item?id=33855071
    - seti0Cha 4y ago
      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.
      - revolvingocelot 4y ago
        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?
        seti0Cha 4y ago
        > I think I've been pretty clear in my desire to not engage in bullshit arguments > What's a "non sequeter", by the way? Lol. Yeah, very clear.
pedrosorio 4y ago
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.
- ajuc 4y ago
  > 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.
  - DontchaKnowit 4y ago
    Sure but this is just bob telling alice to shut the fuck up cause hes already on the same page
    - ajuc 4y ago
      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
aeneasmackenzie 4y ago
Plenty of people consider proof by contradiction a fast one, like all intuitionist mathematicians.

Alice: have you heard of proofs by contradiction?

by ajuc 4y ago

Alice: have you heard of proofs by contradiction?

arthurcolle 4y ago

Bob: Segmentation fault! (core dumped)

revolvingocelot 4y ago

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

pessimizer 4y ago
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.
- revolvingocelot 4y ago
  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...
  - ajuc 4y ago
    Do you believe there's a last prime number? Do you accept Gödel's incompleteness theorems?
    - revolvingocelot 4y ago
      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.
seti0Cha 4y ago
> 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?
- revolvingocelot 4y ago
  >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 https://news.ycombinator.com/item?id=33855071
  - seti0Cha 4y ago
    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.
    - revolvingocelot 4y ago
      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?
      - seti0Cha 4y ago
        > I think I've been pretty clear in my desire to not engage in bullshit arguments > What's a "non sequeter", by the way? Lol. Yeah, very clear.

pedrosorio 4y ago

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.

ajuc 4y ago
> 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.
- DontchaKnowit 4y ago
  Sure but this is just bob telling alice to shut the fuck up cause hes already on the same page
  - ajuc 4y ago
    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

aeneasmackenzie 4y ago

Plenty of people consider proof by contradiction a fast one, like all intuitionist mathematicians.