Hug the Query
post by Eliezer Yudkowsky (Eliezer_Yudkowsky) · 2007-12-14T19:51:37.000Z · LW · GW · Legacy · 22 commentsContents
22 comments
In the art of rationality there is a discipline of closeness-to-the-issue—trying to observe evidence that is as near to the original question as possible, so that it screens off as many other arguments as possible.
The Wright Brothers say, “My plane will fly.” If you look at their authority (bicycle mechanics who happen to be excellent amateur physicists) then you will compare their authority to, say, Lord Kelvin, and you will find that Lord Kelvin is the greater authority.
If you demand to see the Wright Brothers’ calculations, and you can follow them, and you demand to see Lord Kelvin’s calculations (he probably doesn’t have any apart from his own incredulity), then authority becomes much less relevant.
If you actually watch the plane fly, the calculations themselves become moot for many purposes, and Kelvin’s authority not even worth considering.
The more directly your arguments bear on a question, without intermediate inferences—the closer the observed nodes are to the queried node, in the Great Web of Causality—the more powerful the evidence. It’s a theorem of these causal graphs that you can never get more information from distant nodes, than from strictly closer nodes that screen off the distant ones.
Jerry Cleaver said: “What does you in is not failure to apply some high-level, intricate, complicated technique. It’s overlooking the basics. Not keeping your eye on the ball.”1
Just as it is superior to argue physics than credentials, it is also superior to argue physics than rationality. Who was more rational, the Wright Brothers or Lord Kelvin? If we can check their calculations, we don’t have to care! The virtue of a rationalist cannot directly cause a plane to fly.
If you forget this principle, learning about more biases will hurt you, because it will distract you from more direct arguments. It’s all too easy to argue that someone is exhibiting Bias #182 in your repertoire of fully generic accusations, but you can’t settle a factual issue without closer evidence. If there are biased reasons to say the Sun is shining, that doesn’t make it dark out.
Just as you can’t always experiment today, you can’t always check the calculations today.2 Sometimes you don’t know enough background material, sometimes there’s private information, sometimes there just isn’t time. There’s a sadly large number of times when it’s worthwhile to judge the speaker’s rationality. You should always do it with a hollow feeling in your heart, though, a sense that something’s missing.
Whenever you can, dance as near to the original question as possible—press yourself up against it—get close enough to hug the query!
1Jerry Cleaver, Immediate Fiction: A Complete Writing Course (Macmillan, 2004).
2See also “Is Molecular Nanotechnology ’Scientific’?” http://lesswrong.com/lw/io/is_molecular_nanotechnology_scientific.
22 comments
Comments sorted by oldest first, as this post is from before comment nesting was available (around 2009-02-27).
comment by Doug_S. · 2007-12-14T20:20:18.000Z · LW(p) · GW(p)
If you actually watch the plane fly, the calculations themselves become moot for many purposes, and Kelvin's authority not even worth considering.
If the Wright brothers were professional magicians, then would you be less inclined to believe your eyes when you saw the plane fly? ;)
Replies from: Odinn, MugaSofer↑ comment by Odinn · 2013-03-06T05:18:41.816Z · LW(p) · GW(p)
I often wonder how people come around to disbelieving things they've seen with their own eyes. In your hypothetical, you have seen the flight for yourself, but the Brothers are prestidigitators. I can see the validity in thinking "I've just seen something hitherto extraordinary, so let's make sure that any other explanations for what I've seen (like wire-tricks) are less likely than postulate: that plane can really fly!" But I don't think it's constructive to just pattern match "These guys make a living tricking people with unbelievable bologna, so going so far as even SEEING something perpetrated by these hoaxters would make me look stupid. Therefore, I didn't see that plane fly"
comment by Caledonian2 · 2007-12-14T20:33:30.000Z · LW(p) · GW(p)
Arguments from incredulity are fallacious no matter who makes them or how much authority they possess on any subject.
comment by Eliezer Yudkowsky (Eliezer_Yudkowsky) · 2007-12-14T20:34:27.000Z · LW(p) · GW(p)
Doug: If the Wright brothers were professional magicians, then would you be less inclined to believe your eyes when you saw the plane fly?
No, and in related news, the Statue of Liberty just vanishes from time to time...
I guess you're right.
comment by Shakespeare's_Fool · 2007-12-15T04:34:51.000Z · LW(p) · GW(p)
Eliezer,
I agree.
Which is why, since we have the evidence of the background radiation found by Wilson and Penzias and the evidene of the current state of the universe (and since no one has shown me any counter evidence) I no longer believe in the "heat death of the universe" and neither should anyone else.
Evidence before authority.
John
Replies from: DanielLC↑ comment by DanielLC · 2011-11-24T06:41:54.462Z · LW(p) · GW(p)
Which is why, since we have the evidence of the background radiation found by Wilson and Penzias and the evidene of the current state of the universe
How is this evidence against the heat death of the universe?
(and since no one has shown me any counter evidence)
The first and second laws of thermodynamics (conservation of energy and increasing entropy) have been thoroughly tested. The heat death of the universe is implied by these laws.
Replies from: None↑ comment by [deleted] · 2011-11-24T06:46:20.984Z · LW(p) · GW(p)
Surely you need some cosmological assumption as well.
Replies from: DanielLC↑ comment by DanielLC · 2011-11-24T07:52:40.269Z · LW(p) · GW(p)
What do you mean?
Replies from: None↑ comment by [deleted] · 2011-11-24T08:46:40.859Z · LW(p) · GW(p)
That the universe is in thermodynamic equilibrium, for instance.
Replies from: soreff, DanielLC↑ comment by soreff · 2011-11-24T15:08:54.468Z · LW(p) · GW(p)
I agree that cosmological assumptions are needed to predict the heat death of the universe. I'd phrase it as: The expansion has to be slow enough that the effects of the expansion have to not drive the system significantly away from equilibrium. I'm not a cosmologist, so let me give a simplified example of how expansion can produce disequilibrium:
Say we had an insulated cylinder fitted with a piston filled with a gas with two chemical species in equilibrium, a high temperature form, like NO2, and a low temperature form, like N2O4. Say the gas is initially at complete thermal equilibrium (with respect to chemical degrees of freedom - ignore nuclear reactions!). Now yank the piston out faster than the NO2 can dimerize to give N2O4. The gas still cools (the kinetic energy of the molecules gets reduced by an adiabatic expansion - and this happens to the real universe too). But the gas is now left with a chemical degree of freedom in disequilibrium with the (kinetic energy) temperature.
Come to think of it, in the real universe, there is a very close analogy in the period of initial nucleosynthesis. If the expansion had been slow enough to allow full equilibrium to be maintained as the universe expanded and cooled, all that would be left would be iron-56, not hydrogen and helium. None of this violates the first or second law. Approach to thermodynamic equilibrium is inevitable for a closed system with a fixed volume. Changing the volume can drive it out of equilibrium.
The question for the distant future is what the future dynamics of the expansion are, and how they interact with the remaining degrees of freedom in the matter and energy in the universe. This is complex, and some of the parameters are not yet known.
Replies from: shminux↑ comment by Shmi (shminux) · 2011-11-24T17:51:45.947Z · LW(p) · GW(p)
If the expansion had been slow enough to allow full equilibrium to be maintained as the universe expanded and cooled, all that would be left would be iron-56, not hydrogen and helium.
Actually, He-4, once formed, is really hard to break (~2MeV/nucleon, or 20 billion Kelvin above the average temperature, or 1 standard deviation, as you can see from this graph), so the 1/4 ratio of He-4 by mass would have persisted regardless of the cooling rate. The rest would be carbon, oxygen and iron.
Replies from: soreff
↑ comment by soreff · 2011-11-24T18:22:59.078Z · LW(p) · GW(p)
Yes, breaking up He-4 is very endothermic. There is a triple alpha process, which was too slow to proceed much in the big bang, which converts 3 He-4 -> C-12 and is exothermic.
↑ comment by DanielLC · 2011-11-24T19:12:58.077Z · LW(p) · GW(p)
A thermodynamic equilibrium would mean that the decreases in entropy would equal the increases. Since the decreases must be zero by the second law, the increases would also have to be zero. The laws of thermodynamics don't technically say that it has to increase, but there are things that you can't really prevent. If anything accelerates, it will emit gravitational waves, increasing entropy.
Replies from: None↑ comment by [deleted] · 2011-11-24T19:48:47.732Z · LW(p) · GW(p)
I mean that in order for the universe to be in a heat death state, that universe needs to be in thermodynamic equilibrium. You don't get that merely from the first and second laws.
For instance, the universe could expand. If it expands fast enough, the entropy associated with the heat death state could rise faster than its own entropy can increase, kicking it out of heat death. That's what I mean by needing a cosmological assumption.
comment by Eliezer Yudkowsky (Eliezer_Yudkowsky) · 2007-12-15T18:16:43.000Z · LW(p) · GW(p)
Eliezer, where do your strong claims about the causal structure of scientific discourse come from?
I consider them as obvious first-order approximations, especially to the normative structure. Does an authoritative expert cause a hypothesis to become true, so that we can surgically intervene on the truth of a physical theory by giving its adherents more authority? Clearly not. Does an authoritative expert cause the "arguments" to become stronger? Defining the matter normatively makes it clear that the answer is no. If we talk about perceived arguments, then a good expert makes us perceive the arguments as stronger, but that's simply a question of backward inference not causation - like saying that if the sidewalk is slippery this causes us to think it is raining, but does not cause it to rain.
Since I am discussing what we should pay attention to, not what we do pay attention to, it makes sense to discuss the normative causal struture.
Do you have an alternative suggestion? Clearly there are many things that supervene on expert opinion besides valid arguments, which we could coalesce into a Noise node and a Bias node, describing the invalid influences that we think we can't predict and that we think we can systematically predict respectively:
Truth -> Argument -> Expert Belief <- Noise, Bias
This gives us obvious inferences like "If you know the experts will be biased, but you don't understand their arguments apart from authority, you will be less certain of the truth" and "Surgical interventions on bias and on expert belief cannot make a proposition true, or change which non-authoritative propositions are arguments in favor of it".
You probably have that directional causal structure represented in your mind, which makes the above inferences seem plausible; I just wrote it out.
comment by Caledonian2 · 2007-12-15T19:18:53.000Z · LW(p) · GW(p)
Does an authoritative expert cause a hypothesis to become true, so that we can surgically intervene on the truth of a physical theory by giving its adherents more authority? Clearly not. Does an authoritative expert cause the "arguments" to become stronger? Defining the matter normatively makes it clear that the answer is no. If we talk about perceived arguments, then a good expert makes us perceive the arguments as stronger
Using the credibility of the authority as a proxy for the unknown quality of the arguments makes it easier to produce a conclusion, but it reduces the certainty of that conclusion significantly, because an additional assumption has been introduced.
comment by Eric_Blincow3 · 2007-12-15T23:54:19.000Z · LW(p) · GW(p)
Thats an interesting post. Except I have to take issue with one thing.
When I am arguing with people I find we often spend more time debating the whole supporting structure underlying an argument than the point itself. This is most often the case when people have adopted a public opinion as their own. You have to explain to them that the conclusion is wrong because the framework that leads to it is wrong. If that is the case, hugging the query means that you cant stray from the point being discussed to look at fallacies in the thought processes leading up to the false conclusion. So hugging the query presumes that everyone is already on the same page with regard to everything pertinent to the argument except the point under discussion. In some cases, if your going to hug the query, you might as well just concede the point, because the reasoning is built up in such a way that it can really only lead to one conclusion.
comment by steven · 2007-12-16T14:48:18.000Z · LW(p) · GW(p)
"If you actually watch the plane fly, the calculations themselves become moot for many purposes, and Kelvin's authority not even worth considering."
But is that because of screening or just because the probability is so close to 100%? (Maybe this is the same point Doug S. already made.)
comment by Daniel_Humphries · 2007-12-16T18:04:06.000Z · LW(p) · GW(p)
Eric:
I would suggest that what you are doing is "hugging the query" insofar as you try to show that the arguments and assumptions leading to a false conclusion are faulty. Sometimes it's just a long, difficult slog. Arguments about social policy might admit evidence that looks different than the evidence in physics.
Of course, if your sole reason for having the discussion is to lead someone step by step to your pre-determined conclusion, rather than having an honest inquiry of the subject under discussion, you have another problem. ;)