[tescocles]

I don't know if this is quite what you mean, but I've had more than one discussion (and seen many more online on twitter, reddit) that goes something like:

>Alice: say, for the sake of argument, that A is true

>Bob: But A isn't true?

>Alice: Whether A is true or not is a different question. For the purposes of our conversation (that we're talking about the consequences of A being true), it is.

>Bob: But... A isn't true.

>Alice: I give up!

>Bob: I win!

For Bob, it seems to be completely impossible to talk "stipulatively".

It's equal parts frustrating and baffling to me that some people just can't understand the concept of talking about logical conclusions from some starting point independently from the veracity of that starting point, and I'd agree it's one of the big issues with (online) discourse today.

[dataflow]

I've been, and will probably continue to be, on both sides of this. The problem is that not every "A" deserves counterfactual analysis for both parties 100% of the time. As a silly nonpolitical example, imagine if A is "the earth is flat". I would be Bob in that example, because, well... I am not really willing to spend the time and effort required to debate the topic seriously every time it comes up, and I think most people are similar in this respect. It's not about cognitive ability, it's just that most people don't see the point of engaging in every conversation that's based on premises that are manifestly untrue to them.

[seti0Cha]

You are assuming that you are always aware of when you might be wrong. In other words, your judgement on when a counterfactual deserves to be entertained is itself fallible, and is most likely to be wrong when you have emotional commitments around the issue that are preventing you from reasoning well. By refusing to follow a line of reasoning, you are placing yourself beyond the ability to be reasoned with.

I imagine you might dispute that that ever happens to you, and it may be that you are so thoroughly rational that it doesn't. But let me suggest a counterfactual for you: imagine you are not as rational as all that. How would you know? You would never engage in the conversations which would demonstrate this. So, as a general principle, maybe you should not assume that you are.

[dragonwriter]

> You are assuming that you are always aware of when you might be wrong.

No, I think GP is just aware that the risk of missing a useful dialogue needs to be weighed against the risk of wasting time on a fruitless one.

[TeMPOraL]

It's best to be aware of both. Yes, you may meet trolls and hardcore believers of some really stupid things, but if you always assume that anyone who disagrees with you is one of such people, you're bound to end up as one of them yourself.

EDIT:

Perhaps this is another skill, related to counterfactual analysis: being able to consider you're wrong just a tiny bit, even if you're certain you're right, just to reaffirm yourself. Holding the two conflicting states in your mind, in parallel, for however brief a moment. Kind of like speculative execution. Doesn't cost much if the other party is an obvious troll, but can pay off handsomely if you somehow ended up with a strong belief based on badly flawed assumptions.

[dragonwriter]

> but if you always assume that anyone who disagrees with you is one of such people

That’s a strawman. Not being willing to entertain every prospective interlocutor with (as in the upthread poster’s specific example) flat-earth theories is not the same as assuming everyone who disagrees with you is a hardcore believer of some really stupid thing.

[seti0Cha]

Perhaps so. However, I'm happy to let my point stand as a thing to consider when weighing those judgements. Refusing to engage in thought experiments, in my experience, is more often the product of a closed mind than a busy one.

[goodluckchuck]

Being closed minded is a justifiable defense in some circumstances. The ability to consider counter-factuals is often (and perhaps inherently) leakly. I mean, that once someone has entertained an idea, and relied on it to think about secondary and tertiary effects, they’re more likely to believe the premise… even if they have no additional information about the accuracy the initial premise. It’s an effective form of manipulation / gaslighting.

[mcqueenjordan]

Lol, it is not gaslighting/manipulation. Are you really so unable to resist the temptation to believe an idea that you must choose not to even consider it?

Proof by contradiction[1] has quite a number of important results. We shouldn't denigrate that machinery.

[1]: https://en.wikipedia.org/wiki/Proof_by_contradiction

""" G. H. Hardy described proof by contradiction as "one of a mathematician's finest weapons", saying "It is a far finer gambit than any chess gambit: a chess player may offer the sacrifice of a pawn or even a piece, but a mathematician offers the game." """

[dataflow]

Yes, thank you.

[TeMPOraL]

That really depends on the context. I can think of many discussions in which "imagine the Earth is actually flat" would be an interesting counterfactual and a legitimate start of a useful line of reasoning.

But even if (imagine...) I was dealing with a flat-earther, I'd probably listen just to respect someone being able to work with counterfactuals in the first place. There may be something interesting on the other end, perhaps something I could help them rethink. And, if it was ultimately a waste, and then if I kept hitting on "imagine Earth is flat" people, I'd probably just short-circuit my response to "Is this about argument $X for idea $Y? I've heard it before many times, it doesn't work because $Z.".

But, funny thing, I don't think I've ever met a person capable of discussing counterfactuals who also strongly believed in something completely stupid. In practice, being able to work with counterfactuals during conversations - particularly assuming, for a moment, something they disagree with - has been an effective litmus test for me. If they can handle it, we'll have a productive conversation. If they can't, there's no point in talking to them.

[naasking]

> The problem is that not every "A" deserves counterfactual analysis for both parties 100% of the time.

Maybe a counterfactual analysis is not the point, but it's the first step to making some other relevant point, say by formal analogy. You shouldn't shoot down an argument before it even starts. Judge the actual argument when it's presented.

[s1artibartfast]

I think the main problem raised by your statement is that people often don't have a sense of why they are talking or what the conversation is about. This is especially true on the internet, or as far as I can tell people are often just posting the first thing that comes into their mind. Speaking stipulatively may or may not be relevant, and that relevance depends on the subject and purpose at hand

[dataflow]

Or the issue is you can't find a polite way to communicate it at that point. Like in the flat earth case, "your premise is so insane that I don't want to waste another second of my life debating it with you" would... not go over well - neither with the second party, nor with the moderators of the forum facilitating it.

[meany]

I agree that direct debate is a waste of time in these situations, and I as understand, research shows only makes the flat-earther more adamant. In situations like this, I focus on trying to understand what the emotional underlying driver is that moves people to support these kinds of views and see if I can engage with that. Humans are not primarily logical. Our views are heavily driven by need for acceptance by our community or to rationalize our uniqueness/importance, both which relate back to our survival

[dataflow]

> I focus on trying to understand what the emotional underlying driver is that moves people to support these kinds of views and see if I can engage with that. Humans are not primarily logical.

Now imagine if A was "you committed this crime yesterday". There are so many reasons beyond "acting emotionally" over why perfectly logical people wouldn't entertain a premise like that.

[TeMPOraL]

> Now imagine if A was "you committed this crime yesterday". There are so many reasons beyond "acting emotionally" over why perfectly logical people wouldn't entertain a premise like that.

You'd have to have some pretty non-standard circumstances. I have no problem entertaining such counterfactual in a normal discussion. I'd only squirm if there was a risk the conversation would be used against me - e.g. quoted by a journalist, a law enforcement officer, or some crazy rando on Twitter, with the fact that it was a hypothetical conveniently omitted.

[ssklash]

I think you've nailed exactly why most people who "believe" in flat earth theories do so. They get some sort of emotional benefit from it that is not being met otherwise, which in my experience is a sense of community, belonging, or purpose.

[missedthecue]

So if we were talking about conspiracy theories and I were to say, "imagine that the earth were flat. Who would have motivation to hide it?"

You would just have to stop the conversation there out of a complete inability to posit a theoretical in which the earth was flat?

[akiselev]

Honestly.. yeah. That situation is so ridiculous that I can’t give a serious answer. I’d need to spend hours interrogating a flat earth believer just to figure out how to suspend my own disbelief. Question 1: how do you think Magellan’s expedition circumnavigated the planet?

Might as well ask me “imagine gorgokanakawommbledorks were a real thing, who would have motivation to hide it?” WTF is a gorgokanakawommbledork and what does it have to do with a civilization that never even acknowledged them?

[burnished]

I think you are missing some easy answers for that prompt like “no one”. You don’t have to accept their whole constellation of beliefs to accept an arbitrary statement for the purpose of discussion. Hell I think it allows you to make a stronger point - “even if I agreed with you on some of your priors I still think your conclusions are flawed”.

Frankly though from your responses I think your real position is more that you are particularly weary of this topic and/or don’t feel the need to retread topics with new people if previous conversations have been unproductive.

[akiselev]

> Frankly though from your responses I think your real position is more that you are particularly weary of this topic

I actually haven't had many interactions with flat earthers but the answers tend to follow one of two patterns: giant conspiracy in history or giant conspiracy in physics.

I feel like the former can be dismissed out of hand because the provenance of any evidence they present is suspect - if they had the qualifications to even know why provenance is important, they probably wouldn't be flat earthers [1]. Conspiratorial thinking is so popular now that you're right, I just don't have the energy to engage (which makes for some boring Thanksgiving dinners, thank god)

The other response is far more rare and interesting... and most people who hold this view are either trolls or come back around to reason really fast. The only time I've ever run across this kind of flat earther, all it took was to remind them that one of their family members - sitting right next to them in a permanent state of cringe - circumnavigated the globe in their sailboat.

[1] +1 for circular reasoning

[burnished]

I appreciate the pun.

And sure, I think your view point is fair, but I also think you muddied the top level waters a little because the topic at hand was the ability to reason abstractly past a point of contention and your point seems to be that there are signals where you don’t believe the juice is worth the squeeze. Which, yeah, fair.

To relay a related experience I once listened to this guys MLM pitch. The things that seemed to reach this guy the most were conversation points past ‘is there any indication this works that survives a cursory inspection’, like ‘given that this is good and everyone should do it, what happens to the half of humanity that joins and has no one to recruit?’.

>> The only time I've ever run across this kind of flat earther, all it took was to remind them that one of their family members - sitting right next to them in a permanent state of cringe - circumnavigated the globe in their sailboat.

Side note: glorious

[landemva]

> Conspiratorial thinking is so popular now

Maybe there are societal cycles. I read that witch trials were gripping the public attention a couple centuries ago.

[rayiner]

That's fair, but I think there's a clear rule to be applied based on functional and practical considerations, which is to acknowledge that widely held assumptions must be debated in good faith. To take a political example, the majority of people in the world assume that marital unions (which are a feature of virtually every human society) exist primarily for the purpose of birthing and raising children. You can disagree with that premise, you can point out the other areas where society has agreed to deviate from that premise, you can point out the cruel ramifications of that rule in certain cases, etc. But you can't declare that premise ideologically and morally off-limits. Because you can't as a practical matter achieve a functional society by treating a wildly held belief as outside the scope of good faith debate.

[tptacek]

You could have said that about slavery in the 18th century.

You can, in fact, declare some popular premises morally off-limits.

[brhsagain]

The whole point is that it's only "obvious" now in hindsight that slavery is wrong. Now that our society treats that as an axiom, you can say, well, there are some things that are obviously just axiomatically wrong, let's ban those things. But if you were back in the 18th century it wouldn't have been an axiom.

[tptacek]

"All slaves must be set free" was exactly as true in 1750 and it is in 2022. This isn't a historical or sociological analysis; it's moral. If you built a time machine and traveled back to 1750, you could not morally entertain the then-popular norm of slavery.

[suslik]

I am sincerely curious: are you able to provide a criterion or two that would allow me to make objective moral decisions (the possibility of which I think you are postulating)? How do I know slavery is immoral, besides that it is considered immoral in the given cultural context? I am sure an Athenian gentleman 3rd century BC didn't think that way; Aristotle surely didn't - and he spent a lifetime on systematic reasoning, ethics incuded.

[brhsagain]

I think there's actually a big difference between morality and truth, and what you're saying applies to truth and not morality. If you went around telling people about germ theory, you could say, I'm objectively right and you're objectively wrong, here's the proof. The truth is the truth; it's an invariant. It's arrived at through discovery and investigation. Morality is about people fighting to get what they want. The "right answer" is arrived at through conflict and seeing who wins. We live in a society where "slavery is bad" won.

When you say we should ban debate of slavery because it's settled, what you're in effect saying is that society has made a decision and you would like that decision to be final. So would I. But there's nothing final about it. It's not like God has spoken on the matter. Deciding to ban further appeal of the matter is just moral entrepreneurship, not some absolute right answer.

[nec4b]

No you couldn't say that about slavery! Because only a small privileged group was able to have slaves. On the other hand a majority of people gets married or live in a relationship. What a weird comparison you made comparing marriage to slavery.

[tptacek]

I'm obviously not comparing marriage to slavery. I'm observing that at various times, ideas that we today absolutely foreclose on were live debates, or even prevailing norms. In the early 18th century, if you'd gone around saying that all slaves must immediately be freed, and the matter wasn't up for discussion, you'd had been right. But Rayiner's logic could be turned against what you were saying, too.

Just because 51% of people believe something, that doesn't mean we're bound to respect it. If that was true, Wikipedia would be infallible.

[nec4b]

Basically you don't want to have a discussion about something because 50%+ people were wrong about something at some point in history. And you give an example of slavery when rayiner was making a concrete point about marriage. Would ever post on a climate change thread about how once the majority of scientist believed earth was the center of the Universe and were wrong and therefore because majority of scientist was wrong once they are also wrong about the climate change today?

[landemva]

> only a small privileged group was able to have slaves.

That may be a USA-centric view. It differed in other areas.

https://www.historyireland.com/from-baltimore-to-barbary-the...

[rayiner]

Hence my caveat regarding that “functional” and “practical” considerations. If maintaining a functioning social order isn’t the goal, and a bloody civil war is acceptable in pursuit moral ends, then obviously my point doesn’t apply.

[tptacek]

No, of course that's not true. You just haven't set up a coherent classification here. It's easy to come up with comparably black-and-white issues where we did not in fact have to tear down society to resolve them. I can think of 3 off the top of my head.

[rayiner]

All of those issues ripped tears in our society when they were decided by force (court orders being a form of force, backed by the threat of men with guns) instead of building consensus. It’s a civil war on the installment plan. It’s notable that Europe mostly handled those same issues by consensus and is much less internally polarized as a result.

[fallingknife]

Well, seeing as we didn't get rid of slavery, but rather outsourced it, no you can't.

[tptacek]

This is incoherent.

[dp-hackernews]

Is it time for tea?

[funnymony]

A bit tangential, but in discussion with flat earth people, the “A” is “main stream media and education system and scientists are lying”.

Thesis “Earth is flat” can’t be disproved then.

[yarg]

> imagine if A is "the earth is flat"

https://en.wikipedia.org/wiki/Proof_by_contradiction

[ThrowawayTestr]

That you're unable to even entertain the idea is the issue.

[dataflow]

Sorry, what? "I am unwilling to entertain it for the Nth time" does not imply "I am unable to entertain it" or "I have never entertained it".

[synu]

You could spend your whole life entertaining flat earthers if you like, but why?

[Godel_unicode]

Because there’s a large group of people in our society who are aligned along that same “can’t trust science/politicians/MSM” axis. Gaining an understanding of, and empathy for, those people will serve you well and is important for society. Talking with them about why they think what they think is a good way to do that.

[synu]

That’s fair.

[cogman10]

I've had your exact discussion both online and in person, You aren't alone.

Sometimes online, I suspect it's insincere. They know why you are doing the hypothetical, it hurts their position, so instead of engaging with it they become absolutists.

Other times, though (especially easy to see in person) it is VERY real. They simply are not capable of dealing with hypotheticals.

Where that came up the most for me was when tutoring math in college. The abstract nature of math past algebra was just something some people could not grok. They wanted the hard and fast facts. "Ask me to do 7 * 5 and I'll have that answer in an instant, don't ask me riddles about x * 5 = 35".

[nine_k]

Alice need to adapt to Bob's perception if she wants him to listen.

"If we lived in a completely imaginary world where A were true" could address Bob's sensibilities a bit better.

First make yourself heard, then make your point. Otherwise your point falls on deaf ears. This takes some ability to listen and tailor your arguments to fit your audience.

[rukuu001]

"Let's imagine an alternate universe, where A is true. What else would be true in that case?"

[anotherman554]

Can you think of a scenario where you would be playing the role of Bob, not Alice, here? Suppose it went down this way:

Alice: Say, for the sake of argument, Bob beats his wife.

Bob: But I don't beat my wife...

Alice: Whether you beat your wife or not is a different question. For purposes of our conversation about consequences you beat your wife.

In this scenario Bob understands the implication of logical conclusions but considers the conversation to be a trap.

[tbrownaw]

>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.

[ajuc]

Alice: have you heard of proofs by contradiction?

[pedrosorio]

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]

> 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]

Sure but this is just bob telling alice to shut the fuck up cause hes already on the same page

[ajuc]

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

[arthurcolle]

Bob: Segmentation fault! (core dumped)

[aeneasmackenzie]

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

[revolvingocelot]

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]

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]

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]

Do you believe there's a last prime number? Do you accept Gödel's incompleteness theorems?

[seti0Cha]

> 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]

>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

[seti0Cha]

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.

[nootropicat]

The problem with doing this in an adversarial online setting is that it's often used as a trick to make someone admit to some position that's 'close' to the original, and then spin that as agreeing to the original position.

Especially on twitter where post length forces shortcuts which are very easy to maliciously leverage.

In some cases if the assumption is what's being argued itself doing this is an attempt at manipulation, not genuine discussion.

[MaysonL]

if A is false then A implies B is true, whatever the truth value of B is. Thus arguing from a false premise is meaningless.

[josephg]

“If there was a bug in module X, we’d see this exact behaviour…”

“But there’s definitely no bug there! I wrote that code myself!”

These conversations seem pretty useful to me.

[sicp-enjoyer]

That's a nice factoid, but if you read a little further in the logic book you would learn it's quite useful. Proving implications, such a B -> C can be an important step in themselves. It's also essential for proofs by contradiction and proofs of impossibility.

Even if you were right, that particular definition of implication is just convention. There are other logical systems and views that don't interpret it that way.

[netsharc]

If Bob had heard the phrase before, maybe he'd say "I don't deal with hypotheticals". If I were Alice, that would make me see Bob as smart as an amoeba, because even animals deal with "What if" scenarios...