What do professional philosophers believe, and why?

I think that it might help to use the label "Rationalism" instead of "Rationalists" if you talk about dimension as opposed to clusters.

In the case of philosophy of religion I think what's happening is a selection effect: people who believe in theist religion are disproportionately likely to think it worthwhile to study philosophy of religion, i.e. the theism predates their expertise in the philosophy of religion, and isn't a result of it.

I'll give you a slightly different spin on the bias. More evolutionary bias than selection bias.

People who assert that a field is worthwhile are more likely to be successful in that field.

Of course, one could argue that LW regulars get even less rapid feedback on these issues than the professional philosophers do. The philosophers at least are frequently forced to debate their ideas with people who disagree, while LW posters mostly discuss these things with each other - that is, with a group that is self-selected for thinking in a similar way. We don't have the kind of diversity of opinion that is exemplified by these survey results.

It's been shown that expertise is only valuable in fields where there is a short enough and frequent enough feedback loop for a person to actually develop expertise -- and there is something coherent to develop the expertise in

What do you think philosophy is lacking? An (analytical) philosopher who makes a logic error is hauled up very quickly by their peers. That's your feedback loop. So is "something coherent" lacking? Phil. certainly doesn't have a set of established results like engineering, or the more settled areas of science. It does have a lot of necessary skill in formulating, expressing and criticising ideas and arguments. Musicians aren't non-experts just because there is barely such a thing as a musical fact. Philosophy isn't broken science.

It's been shown that expertise is only valuable in fields where there is a short enough and frequent enough feedback loop for a person to actually develop expertise -- and there is something coherent to develop the expertise in. Outside of such fields, experts are just blowhards with status.

I don't disagree with this, but do you happen to have a cite?

I would also point out that feedback which consists solely of the opinions of other experts probably shouldn't count as feedback. Too much danger of groupthink.

The finding that expertise is only valuable in fields where there is a sufficiently short and frequent feedback look plausibly explains why professional philosophers are no better than the general population at answering philosophical questions. However, it doesn't explain the observation that philosophical expertise seems to be negatively correlated with true philosophical beliefs, as opposed to merely uncorrelated. Why are philosophers of religion less likely to believe the truth about religion, moral philosophers less likely to believe the truth about morality, and metaphysicians less likely to believe the truth about reality, than their colleagues with different areas of expertise?

I don't think this is true in every domain. If the domain is bridge building, for example, I have some confidence that the domain experts have built a bridge or two and know what it takes to keep them up and running; if they didn't, they wouldn't have a job. That is, bridge building is a domain in which you are forced to repeatedly make contact with reality, and that keeps your thoughts about bridge building honest. Many domains have this property, but not all of them do. Philosophy is a domain that I suspect may not have this making-contact-with-reality property (philosophers are not paid to resolve philosophical problems, they are paid to write philosophy papers, which means they're actually incentivized not to settle questions); some parts of martial arts might be another, and some parts of psychotherapy might be a third, just so it doesn't sound like I'm picking on philosophy uniquely.

I don't think many people have prior convictions about decision theory before they study it.

You picked literally the most extreme case, where 52.5% of undergraduates answered "insufficiently familiar," followed by 46.1% for A- vs B-theory of time. The average for all other questions was just under 12%, 8.8% for moral realism, 0.9% for free will, 0% for atheism.

For Newcomb most undergrads are not familiar enough with the problem to have an opinion, but people do have differing strong intuitions on first encountering the problem. However, the swing in favor of two boxing for Newcomb from those undergrads with an opinion to target faculty is a relatively large chance in ratio of support from 16:18 to 31:21. Learning about dominance arguments and so forth really does sway people.

I just looked through all the PhilPapers survey questions, comparing undergrads vs target faculty with the coarse breakdown. For each question I selected the plurality non-"Other" (which included insufficient knowledge, not sure, etc) option, and recorded the swing in opinion from philosophy undergraduates to philosophy professors, to within a point.

Now, there is a lot of selection filter between undergraduates and target faculty; the faculty will tend to be people who think philosophy is more worthwhile, keen on graduate education, and will be smarter with associated views (e.g. atheism is higher at more elite schools and among those with higher GRE scores, which correlate with becoming faculty). This is not a direct measure of the effect of philosophy training and study on particular people, but it's still interesting as suggestive evidence about the degree to which philosophical study and careers inform (or otherwise influence) philosophical opinion.

In my Google Doc I recorded an average swing from undergraduates to target faculty of ~10% in the direction of the target faculty plurality, which is respectable but not huge. Compatibilism rises 18 points, atheism 10 points, moral realism 12 points, physicalism 4 points, two-boxing by 15, deontology by 10, egalitarianism by 10. Zombies and personal identity/teletransporter barely move. The biggest swing is ~30 points in favor of non-skeptical realism about the external world.

That said, I agree the LWers who answered the survey questions in a LW thread were overconfident, that the average level of philosophical thinking here is lower quality than you would find in elite philosophy students and faculty (although not uniformly, if for no other reason because some such people read and comment at LW), and that some prominent posters are pretty overconfident (although note that philosophers themselves tend to be very confident in their views despite the similarly confident disagreement of their epistemic peers with rival views, far more than your account would suggest is reasonable, or than I would).

this screams Dunning-Kruger effect.

Please cite the specific part of the original Dunning-Kruger paper which would apply here. I don't think you've read it or understand what the effect actually is.

Compatibilism doesn't belong on that list; a majority of philosophers surveyed agree, and it seems like most opposition is concentrated within Philosophy of Religion, which I don't think is the most relevant subfield. (The correlation between philosophers of religion and libertarianism was the second highest found.)

I'm pretty sure an outside view would say it is LWers rather than domain experts who are more likely to be wrong, even when accounting for the selection-confounding Carl Schulman notes: I don't think many people have prior convictions about decision theory before they study it.

I observe that in some cases this can be both a rational thing believe and simultaneously wrong. (In fact this is the case whenever either a high status belief is incorrect or someone is mistaken about the relevance of a domain of authority to a particular question.)

I've noted it previously, but when the LW consensus are that certain views are not just correct but settled questions (obviously compatibilism re. free will, obviously atheism, obviously one-box, obviously not moral realism etc.), despite the balance of domain experts disagreeing with said consensus, this screams Dunning-Kruger effect.

It does scream that. Indeed, anyone who has literally no other information than that a subculture has a belief along those lines that contradicts an authority that the observer has reason to trust more then Dunning-Kruger is prompted as a likely hypothesis.

Nevertheless: Obviously compatibilism re. free will, obviously atheism, obviously one-box, obviously not moral realism!

The 'outside view' is useful sometimes but it is inherently, by design, about what one would believe if one was ignorant. It is reasoning as though one does not have access to most kinds of evidence but completely confident in beliefs about reference class applicability. In particular in this case it would require being ignorant not merely of lesswrong beliefs but also to be ignorant of philosophophy, philosophy of science and sociology literature too.

but I don't see why one couldn't study aesthetics as 'subjective' (whatever precisely that means), or metaphysics as a skeptic. (In fact, many do each of those things. Just not most.) I guess I can see how devoting your whole life's work to destroying illusions could be a downer, though.

Subjective aesthetics is probably more the realm of psychology (unless it is so subjective that you can't study it). But I'm obviously not saying only Platonists would want to study metaphysics. I'm just saying that the selection effect is sufficient to explain the differences in positions between specialists and non-specialists.

Why does 'free will' make any difference? If Omega can only predict you with e.g. 60% accuracy, that's still enough to generate the problem.

I'm not saying the right answer, i.e., the right decision theory, is a settled question. I'm just saying they lose. This matters. If their family members' or friends' welfare were on the line, as opposed to some spare cash, I strongly suspect philosophers would be less blasé about privileging their pet formal decision-making theory over actually making the world a better place. The units of value don't matter; what matters is that causal decision theory loses, and loses by arbitrarily large amounts.

I don't think controversies over the Axiom of Choice are similar in the right ways to controversies over Newcomb's Problem. In pragmatic terms, we know that true two-boxers will willingly take on arbitrarily large disutility (or give up arbitrarily large utility), inasmuch as they're confident that two-boxing is the right answer. The point can even be put psychologically: To the extent that it's a psychological fact that humans don't assign infinite value to being Causal Decision Theorists, the utility (relative to people's actual values) of following CDT can't outweigh the bad consequences of consistently two-boxing.

I know of no correspondingly strong demonstration that weakening Choice or eliminating LEM leads demonstrably to irrationality (relative to how the world actually is and, in particular, what preferences people actually have).

I would say Newcomb is all about how you view personal identity. But I'm not sure why this comment was directed at me.

Listen, this is like someone who believes the Axiom of Choice saying "constructivist mathematicians are drastically worse at set theory" (because they reject Choice). Newcomb is all about how you view free will. This is not a settled question yet.

To the extent that Newcomb's Problem is 'about how you view free will' people who two box on Newcomb's Problem are confused about free will.

This isn't like constructivist mathematicians being worse at set theory because they reject choice. It's closer to a kindergarten child scribbling in crayon on a Math exam then insisting "other people are bad at Math too therefore you should give me full marks anyway".

I would be interested in seeing how philosophers do on tests of analytical versus intuitive reasoning (I forget the name of the test normally used for gauging this) and ability to narrow down hypotheses when the answers are known and easily verifiable.

Upvoted for understatement.

Quinean reasons. Tegmark's position, as far as I can tell, is that all abstract objects are also physically instantiated (or that the only difference between concrete and abstract objects is indexical). Which I think is plausible-- but I think abstract objects could be an entirely different sort of thing from concrete, physically existing objects, and still exist.

I think Jack meant the sort of modern platonism that philosophers believe, not Tegmark-style platonism. Modern platonism is the position that, as Wikipedia says, abstract objects exist in a sense "distinct both from the sensible external world and from the internal world of consciousness", while in Tegmark's platonism, abstract objects exist in the same sense as the external world, and the external world is a mathematical structure.

I'm afraid that during this comment you are being hilarious, but during that part of your post you were being unintentionally misleading.

Until I went back and compared the numbers I took your description to mean that their dislikes here were much stronger than the ones for other clusters.

And here I just thought you had really strong priors for perfectly equal distribution.

It totally flew over my head then (and I'm probably not the only one). I guess I'm too used to popular science journalism that takes a study with a small correlation or a small effect or a small sample size, and rounds it to the nearest cliche to put a triumphant headline like "SMOKING CAUSES HOMOSEXUALITY", whereas the original study was that in a group of 20 rats, filling their cage with smoke made male-female rat interaction frequency decrease by 7%.

Anti-realism is one of the examples I was thinking of. The survey found more anti-realists in philosophy of science than outside it, probably because those in philosophy of science were more likely to be thinking of instrumentalism, operationalism, or various forms of positivism vs. realism while those outside philosophy of science were more likely to be thinking of idealism vs. realism. Admittedly idealism is another vague, murky concept, but I suppose the most plausible interpretations would include some of the mistakes of the anti-naturalists. But since most anti-realists aren't idealists (especially not those in the philosophy of science), the problems with idealism aren't relevant.

Ernest Nagel[1] discussed the instrumentalism vs. realism debate in his very influential The Structure of Science, and I personally agree with both his conclusion that the issue is far less substantial than it may appear, and his comment that "many scientists as well as philosophers have indeed often used the term ' real' in an honorific way to express a value judgment and attribute a 'superior' status to the things asserted to be real. There is perhaps an aura of such honorific connotations whenever the word is employed, despite explicit avowals to the contrary and certain to the detriment of clarity. For this reason it would be desirable to ban the use of the word altogether" (151). Nagel's views in the philosophy of science were close to those of the positivists, and of course many of the positivists were scientists by training (and it remains true that philosophers of science often have strong backgrounds in science).

It seems to me that some of the debate over reductionism is worsened by realist biases. While many anti-reductionists are motivated by a more general anti-naturalism, there have been many prominent advocates of "non-reductive physicalism" of one kind or another (people like Fodor and Putnam and their followers) who have a different motivation. They seem to be very concerned that reductionism somehow claims that psychological laws and phenomena are somehow not "real" because on reductionism only the physical base is really "real." It seems to me that those mistaken views are an example of the problem Nagel talks about.

[1] Not to be confused with Thomas Nagel..

I'm guessing that you don't really know what anti-realism in philosophy of science looks like. I suspect that most of the non-specialist philosophers who responded also don't really know what the issues are, so this is hardly a knock against you. Scientific realism sounds like it should be right. But the issue is more complicated, I think.

Scientific realists commit to at least the following two theses:

(1) Semantic Realism. Read scientific theories literally. If one theory says that space-time is curved and there are no forces, while the other says that space-time is flat and there are primitive forces (so the two have exactly the same observational consequences in all cases), then the realist says that at most one of the two is true.

(2) Epistemic Realism. In every case, observation and experimentation can provide us with good epistemic (as opposed to pragmatic) reasons to believe that what some single theory, read literally, says about the world.

Denying either of these leads to some form of anti-realism, broadly construed. Positivists, instrumentalists, and pragmatists deny (1), as Einstein seems to have done in at least two cases. Constructive empiricists deny (2) in order to keep a commitment to (1) while avoiding inflationary metaphysics. Structural realists deny one or both of these commitments, meaning that they are anti-realists in the sense of the question at stake.

I'd say the Anti-Naturalism and Anti-Realism clusters are obviously wrong.

I wonder what your definition of obviously wrong is. Is it instrumental, like two-boxing on Newcomb? Bayesian, like theism failing the Occam's razor? Or something else? Or a combination?

Just to make everything more confusing, it turns out that David Hume was not a Humean about laws of nature.

This is a great summary! My confidence that Humeanism is false is not extremely high; but it's high enough for me to think philosophers of science are far too confident of Humeanism relative to the evidence. The main source of uncertainty for me here is that I'm really not clear on what it takes for something to be a 'law of nature'. But if the essential question here is whether extremely strong correlations in fundamental physics call for further explanation, then I side with the 'yeah, some explanation would be great' side. The main worry is that if these events are brute coincidences, we have no Bayesian reason to expect the coincidence to continue into the future. The core intuition underlying non-Humeanism is that some simpler and more unitary mechanism is far more likely to have given rise to such empirical consistency than is such consistency to be the end of the story.

My concern with philosophers of science confidently endorsing Humeanism is that I expect this to be a case of 'I'm supposed to think like a Scientist, and Scientists are skeptical of things, especially weird things we can't directly observe'. Even if Humeanism itself is true, I would be very surprised if most Humeans believe in it for the right reasons.

In some ways this argument parallels the argument Eliezer has with himself over whether our universe is more like first-order logic or more like second-order; first-order logic is similar in some ways to Humeanism, because it doesn't think we need to subsume the instances within a larger generalization in order to fully explain and predict them. (Or, more precisely, it thinks such generalizations are purely anthropocentric, human constructs for practical ends; they give us little if any reason to update in favor of any metaphysical posits.)

Hmm, I may need to reread the paper, but my understanding that they were also using Hume in the context of the question which asked which philosophers or philosophical schools people most identified with.

Thanks; the names were a factor which had me turned around a bit before I saw the 'dimension' clarification, because I thought that those names were referring to one of the groups which claims that name as their referent.

dissolving questions is a fantastic way to get tenure in philosophy.

Can you give examples?

I've had bad experiences of this kind with a bunch of famous philosophers, though the problem doesn't seem to extend to their writing. I think being famous, especially when you're in the presence of the people with whom you are famous, is really, really hard on your rationality.

Judging from what made him smile, he was interested in philosophy only as a competition.

As a display of virtuosity. An instrumental value (verbal dexterity) becomes an end in itself. Technique for technique's sake. Cleverness for cleverness' sake. Not necessarily competition against anyone in particular, but evaluation versus a standard and the general population distribution of those evaluations.

What makes this question

'If my life were on the line, and I really had to come up with the right answer and not just an Interesting and Intuitively Appealing reef of arguments, how confident would I actually be that teleportation is death, is determinately death, and that that's the end of the story?'

different from this question?

Is teleportation death?

Also, what effect do you suppose identifying as philosophers has on philosophers, or adhering to conventions about what it means to be a philosopher? Do you mean that this produces methodological problems?

The problem with that is that people here aren't familiar with many of the concepts. For example, I like Hume's work on the philosophy of science, but I'm not a philosopher and I have no idea what it means for a position to be Humean or non-Humean. I think more people would answer without really understanding what they are answering than would take the time to figure out the questions.

http://lesswrong.com/lw/56q/how_would_you_respond_to_the_philpapers_what_are/

I guess it depends what you mean by 'depending significantly on the world outside our heads'. If they mean it in the trivial sense, then the fractions in all schools should be so close to 1 that you shouldn't be able to get significant differences in correlation out (a covariance, I suppose). Since there was significant variation, I took them to mean something else. If so, that would be likely to mess us up first.

"Omega predicts that you take both boxes, but you are ignorant of the fact. What do you do, given that Omega predicted correctly?"

"Omega makes a prediction that you don't know. What do you do, given that Omega predicted correctly?"

I fail to see the difference between the decision theory used in these two scenarios.

And can you give an example of an untestable statement that could be true but is objectively false? What does it mean for a statement to be objectively unreasonable to believe?