All of Dpar's Comments + Replies

Dpar30

You're absolutely right. I have no problem using indentation for quotes, as a matter of fact I was wondering how to do that, it's his condescending tone that I took issue with. In retrospect though, I should have just ignored it, but let my temper get the best of me. I'll try to keep counter-productive comments to a minimum in the future.

0RobinZ
Indentation happens by putting a greater-than sign at the beginning of the line. Thus: > The quick brown fox jumps over the lazy dog. becomes
Dpar-40

It was a comment on wedrifid's implicit assumption that I should care about what annoys him and bizarre expectation that I would adjust my behavior because I was "prompted" (not asked politely mind you) by him. Not sure what part of that is not obvious to you.

Dpar-40

Duly noted. God forbid I do something that annoys you. Won't be able to live with myself.

8JoshuaZ
Generally, when some minor formatting issue annoys a long-standing member of an internet community it is a good idea to listen to what they have to say. Many internet fora have standard rules about formatting and style that aren't explicitly expressed. These rules are convenient because they make reading easier for everyone. There's also a status/signaling aspect in that not using standard formatting signals someone is an outsider. Refusing to adopt standard format and styling signals an implicit lack of identification with a community. Even if one doesn't identify with a group, the effort it takes to conform to formatting norms is generally small enough that the overall gain is positive.

As always, I recommend against sarcasm, which can hide errors in reasoning that would be more obvious when you speak straightforwardly.

Dpar20

Isn't it an essential criteria of falsifiability to be able to design an experiment that can DEFINITIVELY prove the theory false?

1satt
If I remember rightly, that's where poor old Popper came unstuck: having thought of the falsifiability criterion, he couldn't work out how to rigorously make it flexible. And as no experiment's exactly 100% uppercase-D Definitive, that led to some philosophers piling on the idea of falsifiability, as JoshuaZ said. But more recent work in philosophy of science suggests a more sophisticated way to talk about how falsifiability can work in the real world. The key idea is "severe testing", where a "severe test" is a test likely to expose a specific error in a model, if such an error is present. Those models that pass more, and more severe, tests can be regarded as more useful than those that don't. This approach also disarms the "auxiliary hypotheses" objection JoshuaZ paraphrased; one can just submit those hypotheses to severe testing too. (I wouldn't be surprised to find out that's roughly equivalent to the Bayes net approach SilasBarta mentioned.)
5JoshuaZ
As Robin's explained below Bayesianism doesn't do that. You should also see the works of Lakatos and Quine where they discuss the idea that falsification is flawed because all claims have auxiliary hypotheses and one can't falsify any hypothesis in isolation even if you are trying to construct a neo-Popperian framework.
7RobinZ
That is the criterion which the Bayesian idea of evidence lets you relax. Instead of saying that "you need to be able to define experiments where at least one result would be completely impossible by the theory", a Bayesian will tell you that "you need to be able to define experiments where the probability of one result under the theory is significantly different from the probability of another result". Look at, say, the theory that a coin is weighted towards heads. If you want to be pedantic, no result can "definitely prove" that it is not (unusual events can happen), but an even split of heads and tails (or a weighting towards tails) is much more unusual given that theory than a weighting towards heads. Edit PS: I am totally stealing the meme that "Bayes is a generalization of Popper" from SilasBarta.
Dpar70

Ok, I understand what you mean now. Now that you've clarified what Eliezer meant by anticipated experience my original objection to it is no longer applicable. Thank you for an interesting and thought provoking discussion.

Dpar20

So essentially what you and Eliezer are referring to as "anticipated experience" is just basic falsifiability then?

6Vladimir_Nesov
With a bayesian twist: things don't actually get falsified, don't become wrong with absolute certainty, rather observations can adjust your level of belief.
Dpar80

That's really clever. I always thought that "credible evidence" was a bit redundant actually. I just used as a figure of speech without thinking about, but according to my definition of evidence that it has to be credible is pretty much implicit. It has been made abundantly clear to me, however, that this community's definition differs substantially, so that's the definition I will use when posting here going forward.

Dpar20

Alright, I think I see what you're getting it, but I still can't help but think that your definition of sensory experience is too broad to be really useful. I mean the only type of belief that it seems to filter out is absolute nonsense like "I have a third leg that I can never see or feel", did I get that about right?

1jimrandomh
Falsifiability can be quantified, in bits. If the only test you have for whether something's true or not is something lame like whether it appears in stories or not, then you have a tiny amount of falsifiability. If there is a large supply of experiments you can do, each of which provides good evidence, then it has lots of falsifiability. (This really deserves to be formalized, in terms of something along the lines of expected bits of net evidence, but I'm not sure how to do so, exactly. Expected bits of evidence does not work, because of scenarios where there is a small chance of lots of evidence being available, but a large chance of no evidence being available.)
2Vladimir_Nesov
Yes. It happens all the time. It's one way nonsense protects itself, to persist for a long time in minds of individual people and cultures. (More generally, see anti-epistemology.)
Dpar10

Well that clarifies things quite a bit. I find this definition of evidence surprising, especially in this community, but very interesting. I'll have to sleep on it. Thank you for the references.

Dpar00

You're not addressing my core point though. If the criteria of anticipated experience as you define it is as likely to be satisfied by fallacious beliefs as it is by valid ones, what purpose does it serve?

2Vladimir_Nesov
I addressed that question in this comment; if something is unclear, ask away. The difference is between a belief that is incorrect, and a belief that is not even wrong.
Dpar00

That's fair enough. However, judging by what I've read, this community's definition of evidence seems to constitute just about anything ever written about anything. How would you then differentiate evidence, from rumor, hearsay, speculation, etc.?

3Vladimir_Nesov
Rumor, hearsay, etc. falls under our definition of evidence, just weak evidence, or probably very indirect (for example, if there is a rumor that A, it might constitute evidence against A being true, given other things you know).
6WrongBot
The wiki should be a good starting point for answering this question. What is Evidence? may also be helpful. Short version: rumor, hearsay, and speculation are evidence, albeit of a very weak variety.
Dpar-10

Well, what can I say? I simply don't consider the vague recollection of reading something somewhere credible evidence of anything, and I stand by that. However, the amount of people that took issue with this statement did open my eyes to the fact that the definition of word "evidence" is not as clear cut as I thought it to be. Not sure if there's any way to resolve this difference of opinion though.

8thomblake
As noted by jimrandomh, saying 'credible evidence' does make an effort to differentiate between different sorts of evidence. If your claim was simply that reading something was not evidence, then you should not have to qualify the word when you use it now. I imagine for those of us who seem to be disagreeing with you, we would agree that that does not constitute 'credible evidence' for some values of 'credible'.
8WrongBot
The easy solution is to stop arguing about the definition of evidence. This community uses it to mean one thing, you're using it to mean something else, and any sort of conflict goes away as soon as people make clear which definition they're using. Since this community already has an accepted definition, you would be safe in assuming that that definition is what other posters here have in mind when they use the word "evidence". By the same token, you should probably find a more precise way to refer to the definition of evidence that you are using in order to avoid being misinterpreted.
Dpar-40

All that is indisputably true. But you didn't really answer my question on whether or not you give enough consideration to what's written in a fairy tale (not whether or not it's written, not who it's written by, but the actual claims made therein) to truly consider it evidence to be incorporated into or excluded from your model of the world.

2wedrifid
That is because it is a bad question and one of a form for which you have already received responses.
2Vladimir_Nesov
Evidence isn't usually something you "include" in your model of the world, it's something you use to categorize models of the world into correct and incorrect ones. Evidence is usually something not interesting in itself, but interesting instrumentally because of the things it's connected to (caused by).
Dpar00

How would you learn that there are no ghosts? You form the belief "there are ghosts" which leads to the anticipated experience (by your definition of such) that "I will read about ghosts in a book", you go and read about ghosts in a book. Criteria met, belief validated. Same goes for UFOs, psychics, astrology etc. What value does the concept of anticipated experience have if it fails to filter out even the most common fallacious beliefs?

4Vladimir_Nesov
That there are books about ghosts is evidence for ghosts existing (but also for lots of other things). There are also arguments against this hypothesis, both a priori and observational. A good model/theory also explains why you'd read about ghosts even though there is no such thing.
Dpar00

You seem to place a good deal of value on the concept of anticipated experience, but you give it a definition that's so broad that the overwhelming majority of beliefs will meet the criteria. If the belief in ghosts for instance can lead to the anticipated experience of reading about them in a book, what validity does the notion have as a means of evaluating beliefs?

2Vladimir_Nesov
When a belief (hypothesis) is about reality, it responds to new evidence, or arguments about previously known evidence. It's reasonable to expect that as a result, some beliefs will turn out incorrect, and some certainly correct. Either way it's not a problem: you do learn things about the world as a result, whatever the conclusion. You learn that there are no ghosts, but there are rainbows. The problem are the beliefs that purport to be speaking about reality, but really don't, and so you become deceived by them. Not being connected to reality through anticipated experience, they take your attention where there is no use for them, influence your decisions for no good reason, and protect themselves by ignoring any knowledge about the world you obtain. It is a great heuristic to treat any beliefs that don't translate into anticipated experience with utmost suspicion, or even to run away from them in horror.
Dpar-30

So you would then agree that merely the fact that something is written SOMEWHERE, does not automatically qualify it as evidence?

(Incidentally that is my original point, which in spite of seeming as common sense as common sense can be, has attracted a surprising amount of disagreement.)

6Unknowns
There may be sense in which this is common sense, but you were purposely using it tendentiously, which is why people responded in the technical way that they did. Eliezer said that he read something "somewhere", obviously intending to say that he read it somewhere that he considered trustworthy at the time, not in a fairy tale.
8Cyan
You have to specify what it purports to be evidence of before I can give you an answer that isn't a tangent. Edited to add: Maybe I can do better than the above sentence. I affirm that the existence of this book is negligible but not strictly zero evidence for the claims detailed therein.
Dpar-10

Vladimir, Cyan, and jimrandomh, since you essentially said the same thing, consider this reply to be addressed to all three of you.

Answer me honestly, when reading a fairy tale, do you really stop to consider what's written there, qualify its worth as evidence, and compare it to everything else you know that might contradict it, before making the decision that the probability of the fairy tale being true is extremely low? Do you really not just dismiss it offhand as not true without a second thought?

4Vladimir_Nesov
Immediate observation is only that something is written. That it's also true is a theoretical hypothesis about that immediate observation. That what you are reading is a fairy tale is evidence against the things written there being true, so the theory that what's written in a fairy tale is true is weak. On the other hand, the fact that you observe the words of a given fairy tale is strong evidence that the person (author) whose name is printed on the cover really existed.
5Oligopsony
No, but only because that would be cognitively burdensome. We're boundedly rational.
5Cyan
When I pick up a work of fiction, I do not spend time assessing its veracity. If I read a book of equally fantastic claims which purports to be true, I do spend a little time. You might want to peruse bounded rationality for an overview.
Dpar10

I agree wholeheartedly that there are valid beliefs that don't translate into anticipated experience. As a matter of fact what's written there was pretty much the exact point that I was trying to make with my very first response in this topic.

Does that not, however, contradict the OP's assertion that "Every guess of belief should begin by flowing to a specific guess of anticipation, and should continue to pay rent in future anticipations. If a belief turns deadbeat, evict it."? That's what I took issue with to begin with.

2Vladimir_Nesov
It does contradict that assertion, but not at first approximation, and not in the sense you took the issue with. You have to be very careful if a belief doesn't translate into anticipated experience. Beliefs about historical facts that don't translate into anticipated experience (or don't follow from past experience, that is observations) are usually invalid.
Dpar00

Well I didn't think I needed to clarify that I'm not questioning whether or not something that's written is really written. Of course, I'm questioning the truthfulness of the actual statement.

Or not so much it's truthfulness, but rather whether or not it can be considered evidence. Though I realize that you take issue with arguing over word definitions, to me the word evidence has certain meaning that goes beyond every random written sentence, whisper or rumor that you encounter.

Cyan100

Though I realize that you take issue with arguing over word definitions, to me the word evidence has certain meaning that goes beyond every random written sentence, whisper or rumor that you encounter.

Around these parts, a claim that B is evidence for A is a taken to be equivalent to claiming that B is more probable if A is true than if not-A is true. Something can be negligible evidence without being strictly zero evidence, as in your example of a fairy story.

5Vladimir_Nesov
The fact that something is written, or not written, is evidence about the way world is, and hence to some extent evidence about any hypothesis about the world. Whether it's strong evidence about a given hypothesis is a different question, and whether the statement written/not written is correct is yet another question. (See also the links from this page.)
Dpar00

Fair enough. So if, on your authority, the OP believes that reading about something is anticipated experience, does that not then cover every rumor, fairy tale, and flat out non-sense that has ever been written? What then would be an example of a belief that CANNOT be connected to an "anticipated experience"?

3Vladimir_Nesov
See this comment on the first part of your question and this page on the second (but, again, there are valid beliefs that don't translate into anticipated experience).
Dpar-10

"This doesn't remotely follow and is far weaker evidence than other available sources. For a start, everyone knows that you get to Oz with tornadoes and concussions."

Let's not get bogged down in the specific procedure of getting to Oz. My point was that if you truly adapt merely seeing something written somewhere as your standard for evidence, you commit yourself to analyzing and weighing the merits of EVERYTHING you read about EVERYWHERE. Do you mean to tell that when you read a fairy tale you truly consider whether or not what's written there i... (read more)

1[anonymous]
This doesn't remotely follow either. Go and research the concept of evidence more. I care little about your signature. I merely describe the social behaviour of humans. What actually does annoy me is if people refuse to use markdown syntax for quotes once they have been prompted. Click the help link below the comment box - consider yourself prompted.

Let's not get bogged down in the specific procedure of getting to Oz. My point was that if you truly adapt merely seeing something written somewhere as your standard for evidence, you commit yourself to analyzing and weighing the merits of EVERYTHING you read about EVERYWHERE.

No, you can acknowledge that something is evidence while also believing that it's arbitrarily weak. Let's not confuse the practical question of how strong evidence has to be before it becomes worth the effort to use it ("standard of evidence") with the epistemic question ... (read more)

4Vladimir_Nesov
The fact that something is really written is true; whether it implies that the written statements themselves are true is a separate theoretical question. Yes, ideally you'd want to take into account everything you observe in order to form an accurate idea of future expected events (observable or not). Of course, it's not quite possible, but not for the want of motivation.
Dpar120

Fair enough. It's a habit of mine that I'm not married to. If members of this board take issue with it, I can stop.

Dpar10

Very interesting read on disputing definitions. While the solution proposed there is very clever and elegant, this particular discussion is complicated by the fact that we're discussing the statements of a person who is not currently participating. Coming up with alternate words to describe our ideas of what "sensory experience" means does nothing to help us understand what he meant by it. Incidentally this is why I didn't want to get drawn into this debate to begin with.

Also -- "consider me having a special insight into the intended meaning" -- on what grounds shall I consider your having such special insight?

2Vladimir_Nesov
I've closely followed Yudkowsky's work for a while, and have a pretty good model of what he believes on topics he publicly discusses.
2Cyan
At the bottom of the sidebar at the bottom, you will find a list of top contributors; Vladimir Nesov is on the list.
4Unknowns
Yes, ghost stories are evidence for the existence of ghosts. Just not very strong evidence. There can be indirect sensory evidence as well as direct.
Dpar-40

So the fact that something was written somewhere is sufficient to meet your criteria for considering it evidence? I take it you have actually tried clicking your heels to check whether or not you would be teleported to Oz then?

Also, does my signing my comments offend you?

DP

4wedrifid
Yes. It's really sucky evidence. This doesn't remotely follow and is far weaker evidence than other available sources. For a start, everyone knows that you get to Oz with tornadoes and concussions. It makes you look like an outsider who isn't able to follow simple social conventions and may have a tendency towards obstinacy. (Since you asked...)

Also, does my signing my comments offend you?

It hurts aesthetically by disrupting uniformity of standard style.

Dpar0-1

So reading about something in a book is a sensory experience now? I beg to differ. A sensory experience of The Crusades would be witnessing them first hand. The sensory experience of reading about them is perceiving patterns of ink on a piece of paper.

DP

Edit: Also, I think that RobinZ didn't state that as something that she believed, she stated that as something that she believed the OP meant. It's that subjective interpretation of his position that I didn't want to debate. If you wish to adapt that position as your own and debate its substance, we certainly can.

0Vladimir_Nesov
You are disputing definitions. Reading something in a book is a sort of thing you'd change expectation about depending on your model of the world, as are any other observations. If your beliefs influence your expectation about observations, they are part of your model of reality. On the other hand, if they don't, they are sometimes too part of your model of reality, but it's a more subtle point. And returning to your earlier concerns, consider me having a special insight into the intended meaning, and proving counterexample to the impossibility of continuing the discussion. Reading something in a history book definitely counts as anticipated experience.
4Oligopsony
What's important isn't the number of degrees of removal, but that the belief's being true corresponds to different expected sensory experiences of any kind at all than its being false. The sensory experience of perceiving patterns of ink on a piece of paper counts. Now you could say: "reading about the Crusades in history books is strong evidence that 'the Crusades happened' is the current academic consensus," and you could hypothesize that the academic consensus was wrong. This further hypothesis would lead to further expected sensory data - for instance, examining the documents cited by historians and finding that they must have been forgeries, or whatever.
Dpar-10

I stated that taking the OP's reasoning to its logical conclusion requires one to "evict" all beliefs in everything that one has not, and does not anticipate to, personally see, hear, smell, taste, or touch. RobinZ responded by saying that the OP's point is less strong than I think. Since two (presumably) reasonable people can disagree on what the OP meant, his point, as it is written, is by definition ambiguous.

Where do we go from here other than debate what he really meant? What is the point of such debate since neither of us has any special i... (read more)

5thomblake
Right, but RobinZ was not arguing against this claim (depending on what you mean by 'personally' here) but rather pointing out that your reasoning was flawed. RobinZ pointed out that your belief that the crusades took place affects your sensory experience; if you believe they happened, then you should anticipate having the sensory experience of seeing them in the appropriate place in a history book, if you were to check. If you thought that your belief that the crusades happened did not imply any such anticipated experiences, then yes, it would be worthless and on the same level as belief in an invisible dragon in your garage.
Dpar20

My argument is what I stated, nothing more. Namely that there is nothing unreasonable about assuming that a perfect stranger that you're having a casual conversation with is not trying to deceive you. I already laid out my reasoning for it. I'm not sure what more I can add.

DP

Dpar20

First of all, calling speech "human telepathy" strikes me as a little pretentious, as well as inaccurate, since the word "telepathy" is generally accepted to have supernatural connotations. Speech is speech; no need to complicate the concept.

Secondly, the article you linked seemed a little rambling and without a clear point. All I was able to take away from it is that the meaning of words is relative. If that's the case then I respond with "well, duh!"; if I missed a deeper point, please enlighten me.

Finally, when you take it ... (read more)

3thomblake
You misunderstand. Vladimir Nesov was not claiming that you don't believe that the author's intended meaning is ambiguous. Rather, he was claiming that your belief that "the author's intended meaning is ambiguous" is false, or at least not enough to constitute a good reason for stopping the discussion. The point of calling speech 'human telepathy' in this instance is that you claimed there's no way to know what the author was thinking since we "can't read his mind". But there is a way to know what the author was thinking to some extent, so by reading your own reasoning backwards we therefore indeed can read minds.
Dpar00

I was going to write a more detailed reply, but then realized that any continued discussion will require us to debate what exactly the OP meant to say in his post, which is pointless since neither of us can read his mind. So let's just call it a day.

DP

3Vladimir_Nesov
This is something of a fallacy of gray. Of course we can read his mind, through the power of human telepathy, by reading more on the same topic. We can't read minds perfectly, but perfect knowledge is never available anyway, and unless you can point out the specific uncertainty you have that decides the discussion, there is no sense in requiring more detail. You might want to stop the discussion for other reasons, but the reason you stated rings false.
Dpar20

I presume that you have encountered liars in the real world as well. Do you, on that basis, habitually assume that a random stranger engaging in casual conversation with you is a liar?

My point is that pathological liars are a small minority. So if you're dealing with a person that you know absolutely nothing about, and who does not have any conceivable reason to lie to you, there is nothing unreasonable in assuming that he's telling you the truth, unless you have factual evidence (i.e. you have accurate, verifiable knowledge of ambulance policies) that contradicts what he's saying.

DP

4persephonehazard
"Do you, on that basis, habitually assume that a random stranger engaging in casual conversation with you is a liar?" Yes. Absolutely. Almost /everyone/ lies to complete strangers sometimes. Who among us has never given an enhanced and glamourfied story about who they are to a stranger they struck up a conversation with on a train? Never? Really? Not even /once/?
6RobinZ
I think at this point the questions have become (a) "how many bits of evidence does it take to raise 'someone is lying' to prominence as a hypothesis?" and (b) "how many bits of evidence can I assign to 'someone is lying' after evaluating the probability of this story based on what I know?" I believe your argument is that a > b (specifically, that a is large and b is small), where the post asserts that a < b. I'm not going to say that's unreasonable, given that all we know is what Eliezer Yudkowsky wrote, but often actual experience has much more detail than any feasible summary - I'm willing to grant him the benefit of the doubt, given that his tiny note of discord got the right answer in this instance.
Dpar40

What about knowledge for the sake of knowledge? For instance I don't anticipate that my belief that The Crusades took place will ever directly affect my sensory experiences in any way. Does that then mean that this belief is completely worthless and on the same level as the belief in ghosts, psychics, phlogiston, etc.?

Wouldn't taking your chain of reasoning to its logical conclusion require one to "evict" all beliefs in everything that one has not, and does not anticipate to, personally see, hear, smell, taste, or touch? After all, how much personal sensory experience do you have that confirms the existence of atoms, for example?

DP

2MarsColony_in10years
The LessWrong FAQ says that there is value in replying to old content, so I'm commenting in hopes that it is useful to someone in the future, and just for the sake of organizing my thoughts. I would have phrased this differently than Yudkowsky, but I think I understand the concept he was getting at when he gave this example: His point is that this is just semantics. It makes no difference to the world whether we label something "post-utopian" or "aegffsdfa eereraksrfa" or anything else. The words you read in the book will be the same. The reason I don’t like this example is that, if I actually knew some literary jargon, I might get some real verifiable information that does actually mean I should expect a specific kind of sensory experience. It’s just that the classification scheme is arbitrary, and so is my belief that one classification scheme is "correct". The label is just a label, so arguing about classification schemes is just semantics. Using this definition, your belief that the crusades took place would affect what sorts of things you would expect to read, and what sorts of archeological finds you would expect to find if you went looking for them. However, if you believe that the crusades marked the beginning of the high middle ages, that would just be semantics. We could say that the middle ages started at the sacking of Rome, or we could make a label like "dark ages" to describe the intermediary period. What we call it and how we classify it makes no difference in the actual reality of history. It's just semantics.
3RobinZ
Belatedly: Welcome to Less Wrong! Please feel free to introduce yourself.
6RobinZ
I think Eliezer's point is less strong than you think: for one thing, reading a history book is a sensory experience, and fewer history books would proclaim that The Crusades occurred in worlds where they had not than in worlds where they had.
Dpar00

The author did not mention anything about an exceptionally high percentage of liars in IRC relative to the general population (which would be quite relevant to his statement) therefore there's no reason to believe that such had been HIS experience in the past.

Given that, there is no reason for HIM to presume that the percentage of compulsive liars in IRC would different from the general population. YOUR experiences may, of course, be drastically different, but they are not the subject of discussion here.

DP

-7MrPineapple
Dpar-10

I read somewhere that if spin about and click my heels 3 times I will be transported to the land of Oz. Does that qualify as a concrete reason to believe that such a land does indeed exist?

DP

thomblake100

I read somewhere that if spin about and click my heels 3 times I will be transported to the land of Oz. Does that qualify as a concrete reason to believe that such a land does indeed exist?

That indeed serves as evidence for that fact, though we have much stronger evidence to the contrary.

N.B. You do not need to sign your comments; your username appears above every one.

Dpar10

Which, as I said later on in the same paragraph, is irrational and unlikely behavior. Therefore, when lacking any factual evidence, the reasonable presumption is that that's not the case.

DP

4RobinZ
I think many of us have actually encountered liars on the Internet. I'm not sure what you mean when you say "lacking any factual evidence".
Dpar-10

The level of "trust" you have in a person should be inversely proportional to the sensationalism of the claim that he's making.

If a person tells you he was abducted by a UFO, you demand evidence.

If a person tells you that on the way to work he slipped and fell down, and you have no concrete reason to doubt the story in particular or the person in general, you take that at face value. It is a reasonable assumption that a perfect stranger in all likelihood will NOT be delusional or a compulsive liar.

DP

1tel
That makes sense if you're only evaluating complete strangers. In other words, your uncertainty about the population-inferred trustworthiness of a person is pretty high and so instead the mere (Occam Factor style) complexity of their statement is the overruling component of your decision. In the stated case, this isn't a totally random stranger. I feel quite justified in having a less-than uninformative prior about trusting IRC ghosts. In this case, my rationally acquired prejudice overrules in inference about the truth of even somewhat ordinary tales.
Dpar10

I don't see that you did anything at all irrational. You're talking to a complete stranger on the internet. He doesn't know you, and cannot have any possible interest in deceiving you. He tells you a fairly detailed story and asks for you advice. For him to make the whole thing up just for kicks is an example of highly irrational and fairly unlikely behavior.

Conversely, a person's panicking over chest pains and calling the ambulance is a comparatively frequent occurrence. Your having read somewhere something about ambulance policies does not amount to hav... (read more)

0[anonymous]
I'm not sure of the particulars of your situation, but I personally encounter people lying on the internet orders of magnitude more times than I do people having chest pains.
7Sniffnoy
Wait, why not?

You're talking to a complete stranger on the internet. He doesn't know you, and cannot have any possible interest in deceiving you.

There's plenty of evidence that some people (a smallish minority, I think) will deceive strangers for the fun of it.