In 2009, David Bourget and David Chalmers ran the PhilPapers Survey (results, paper), sending questions to "all regular faculty members" at top "Ph.D.-granting [philosophy] departments in English-speaking countries" plus ten other philosophy departments deemed to have "strength in analytic philosophy comparable to the other 89 departments".

Bourget and Chalmers now have a new PhilPapers Survey out, run in 2020 (results, paper). I'll use this post to pick out some findings I found interesting. Keep in mind that I'm an opinionated LessWrong contributor focusing on topics and results that dovetail with things I'm curious about (e.g., 'why do academic decision theorists and LessWrong decision theorists disagree so much?'), not giving a neutral overview of the whole 100-question survey.

The new survey's target population consists of:

(1) in Australia, Canada, Ireland, New Zealand, the UK, and the US: all regular faculty members (tenuretrack or permanent) in BA-granting philosophy departments with four or more members (according to the PhilPeople database); and (2) in all other countries: English-publishing philosophers in BA-granting philosophy departments with four or more English-publishing faculty members.

In order to make comparisons to the 2009 results, the 2020 survey also looked at a "2009-comparable departments" list selected using similar criteria to the 2009 survey:

It should be noted that the “2009-comparable department” group differs systematically from the broader target population in a number of respects. Demographically, it includes a higher proportion of UK-based philosophers and analytic-tradition philosophers than the target population. Philosophically, it includes a lower proportion of theists, along with many other differences evident in comparing 2020 results in table 1 (all departments) to table 9 (2009-comparable departments).

Based on this description, I expect the "2009-comparable departments" in the 2020 survey to be more elite, influential, and reasonable than the 2020 "target group", so I mostly focus on 2009-comparable departments below. In the tables below, if the row doesn't say "Target" (i.e., target group), the population is "2009-comparable departments".

Note that in the 2020 survey (unlike 2009), respondents could endorse multiple answers.


1. Decision theory

Newcomb's problem: The following groups (with n noting their size, and skipping people who skipped the question or said they weren't sufficiently familiar with it) endorsed the following options in the 2020 survey:

Groupn     one box two boxesdiff
Philosophers (Target)107131%39%8%
Decision theorists (Target)4821%73%58%
Decision theorists2223%73%50%

5% of decision theorists said they "accept a combination of views", and 9% said they were "agnostic/undecided".

I think decision theorists are astonishingly wrong here, so I was curious to see if other philosophy fields did better.

I looked at every field where enough surveyed people gave their views on Newcomb's problem. Here they are in order of 'how much more likely are they to two-box than to one-box':

Groupn     one box two boxesdiff
Philosophers of gender, race, and sexuality1323%54%31%
20th-century-philosophy specialists2313%43%30%
Social and political philosophers6219%48%29%
Philosophers of law1414%43%29%
Phil. of computing and information (Target)1822%50%28%
Philosophers of social science2433%58%25%
Philosophers of biology2030%55%25%
General philosophers of science5326%51%25%
Philosophers of language10025%47%22%
Philosophers of mind9625%45%20%
Philosophers of computing and information520%40%20%
19th-century-philosophy specialists1010%30%20%
Philosophers of action3228%47%19%
Logic and philosophy of logic5826%43%17%
Philosophers of physical science2528%44%16%
Normative ethicists10232%42%10%
Philosophers of religion1533%40%7%
Philosophers of mathematics1932%37%5%
17th/18th-century-philosophy specialists3931%36%5%
Applied ethicists5034%38%4%
Philosophers of cognitive science5032%36%4%
Greek and Roman philosophy specialists1741%29%-12%

(Note that many of these groups are small-n. Since philosophers of computing and information were an especially small and weird group, and I expect LWers to be extra interested in this group, I also looked at the target-group version for this field.)

Every field did much better than decision theory (by the "getting more utility in Newcomb's problem" metric). However, the only fields that favored one-boxing over two-boxing was ancient Greek and Roman philosophy, and aesthetics.

After those two fields, the best fields were philosophy of cognitive science, applied ethics, metaphilosophy, philosophy of mathematics, and 17th/18th century philosophy (only 4-5% more likely to two-box than one-box), followed by philosophy of religion, normative ethics, and metaphysics.

My quick post-hoc, low-confidence guess about why these fields did relatively well is (hiding behind a spoiler tag so others can make their own unanchored guesses):

 My inclination is to model the aestheticians, historians of philosophy, philosophers of religion, and applied ethicists as 'in-between' analytic philosophers and the general public (who one-box more often than they two-box, unlike analytic philosophers). I think of specialists in those fields as relatively normal people, who have had less exposure to analytic-philosophy culture and ideas and whose views therefore tend to more closely resemble the views of some person on the street.

This would also explain why the "2009-comparable departments", who I expected to be more elite and analytic-philosophy-ish, did so much worse than the "target group" here.

I would have guessed, however, that philosophers of gender/race/sexuality would also have done relatively well on Newcomb's problem, if 'analytic-philosophy-ness' were the driving factor.

I'm pretty confused about this, though the small n for some of these populations means that a lot of this could be pretty random. (E.g., network effects: a single just-for-fun faculty email thread about Newcomb's problem could convince a bunch of  philosophers of sexuality that two-boxing is great. Then this would show up in the survey because very few philosophers of sexuality have ever even heard of Newcomb's problem, and the ones who haven't heard of it aren't included.)

At the same time, my inclination is to treat philosophers of cognitive science, mathematics, normative ethics, metaphysics, and metaphilosophy as 'heavily embedded in analytic philosophy land, but smart enough (/ healthy enough as a field) to see through the bad arguments for two-boxing to some extent'.

There's also a question of why cognitive science would help philosophers do better on Newcomb's problem, when computer science doesn't. I wonder if the kinds of debates that are popular in computer science are the sort that attract people with bad epistemics? ('Wow, the Chinese room argument is amazing, I want to work in this field!') I really have no idea, and wouldn't have predicted this in advance.

Normative ethics also surprises me here. And both of my explanations for 'why did field X do well?' are post-hoc, and based on my prior sense that some of these fields are much smarter and more reasonable than others.

It's very plausible that there's some difference between the factors that make aestheticians one-box more, and the factors that make philosophers of cognitive science one-box more. To be confident in my particular explanations, however, we'd want to run various tests and look at various other comparisons between the groups.

The fields that did the worst after decision theory were philosophy of gender/race/sexuality, 20th-century philosophy, philosophy of language, philosophy of law, political philosophy, and philosophy of biology, of social science, and of science-in-general.

A separate question is whether academic decision theory has gotten better since the 2009 survey. Eyeballing the (small-n) numbers, the answer is that it seems to have gotten worse: two-boxing became even more popular (in 2009-comparable departments), and one-boxing even less popular:

n=31 for the 2009 side of the comparison, n=22 for the 2020 side. The numbers above are different from the ones I originally presented because Bourget and Chalmers include "skip" and "insufficiently familiar" answers, and exclude responses that chose multiple options, in order to make the methodology more closely match that of the 2009 survey.


2. (Non-animal) ethics

Regarding "Meta-ethics: moral realism or moral anti-realism?":

Groupn               moral realism  moral anti-realism
Philosophers (Target)171962%26%
Applied ethicists6467%23%
Normative ethicists13274%16%

Regarding "Moral judgment: non-cognitivism or cognitivism?":

Groupn               cognitivism  non-cognitivism
Philosophers (Target)163669%21%
Applied ethicists6276%23%
Normative ethicists13282%14%

Regarding "Morality: expressivism, naturalist realism, constructivism, error theory, or non-naturalism?":

Groupn        non-natnat realismconstructexpresserror
Philosophers (Target)102427%32%21%11%5%
Applied ethicists4020%35%38%5%0%
Normative ethicists9034%36%21%8%1%

Regarding "Normative ethics: virtue ethics, consequentialism, or deontology?" (putting in parentheses the percentage that only chose the option in question):

Groupn               deontology consequentialismvirtue ethicscombination
All (Target)174132% (20%)31% (21%)37% (25%)16%
All63137% (23%)32% (22%)31% (19%)17%
Applied...6356% (33%)38% (22%)33% (8%)27%
Normative...13246% (27%)32% (20%)36% (17%)25%
Meta...9444% (28%)32% (22%)24% (13%)19%

Excluding responses that endorsed multiple options, we can see that normative ethicists have moved away from deontology and towards virtue ethics since 2009, though deontology is still the most popular:

30 normative-ethicist respondents also wrote in "pluralism" or "pluralist" in the 2020 survey.

Regarding "Trolley problem (five straight ahead, one on side track, turn requires switching, what ought one do?): don't switch or switch?":

Groupn               switch  don't switch
Philosophers (Target)173663%13%
Applied ethicists6371%13%
Normative ethicists13270%13%

Regarding "Footbridge (pushing man off bridge will save five on track below, what ought one do?): push or don't push?":

Groupn               push  don't push
Philosophers (Target)174022%56%
Applied ethicists6324%63%
Normative ethicists13217%70%

Regarding "Human genetic engineering: permissible or impermissible?":

Groupn               permissibleimpermissible
Philosophers (Target)105962%19%
Applied ethicists3985%8%
Normative ethicists8369%12%

Regarding "Well-being: hedonism/experientialism, desire satisfaction, or objective list?":

Groupn               hedonismdesire satisfactionobjective list
Philosophers (Target)96710%19%53%
Applied ethicists4316%26%56%
Normative ethicists9011%21%63%

Moral internalism "holds that a person cannot sincerely make a moral judgment without being motivated at least to some degree to abide by her judgment". Regarding "Moral motivation: externalism or internalism?":

Groupn               internalism  externalism
Philosophers (Target)142941%39%
Applied ethicists5753%37%
Normative ethicists12834%51%

One of the largest changes in philosophers' views since the 2009 survey is that philosophers have somewhat shifted toward externalism. In 2009, internalism was 5% more popular than externalism; now externalism is 3% more popular than internalism.

(Again, the 2009-2020 comparisons give different numbers for 2020 in order to make the two surveys' methodologies more similar.)


3. Minds and animal ethics

Regarding "Hard problem of consciousness (is there one?): no or yes?":

Groupn         yesno
Philosophers (Target)146862%30%
Philosophers of computing and information (Target)1844%50%
Philosophers of cognitive science4048%50%
Philosophers of mind9162%34%

Regarding "Mind: non-physicalism or physicalism?":

Groupn         physicalismnon-physicalism
Philosophers (Target)173352%32%
Phil of computing and information (Target)2564%24%
Philosophers of cognitive science7378%12%
Philosophers of computing and information560%20%
Philosophers of mind13560%26%

Regarding "Consciousness: identity theory, panpsychism, eliminativism, dualism, or functionalism?":

Philosophers (Target)102022%5%33%13%8%
Phil of computing (Target)1625%19%31%0%0%
Phil of cognitive science4314%12%40%19%2%
Philosophers of mind9524%2%38%12%10%

Regarding "Zombies: conceivable but not metaphysically possible, metaphysically possible, or inconceivable?" (also noting "agnostic/undecided" results):

Philosophers (Target)161016%37%24%11%
Phil of computing (Target)2429%25%17%8%
Phil of cognitive science7224%50%11%6%
Phil of computing520%40%20%0%
Philosophers of mind13220%51%17%3%

My understanding is that the "psychological view" of personal identity more or less says 'you're software', the "biological view" says 'you're hardware', and the "further-fact view" says 'you're a supernatural soul'. Regarding "Personal identity: further-fact view, psychological view, or biological view?":

Groupn  biologicalpsychologicalfurther-fact
Philosophers (Target)161519%44%15%
Phil of computing... (Target)2322%70%4%
Philosophers of cognitive science6926%55%6%
Philosophers of computing...540%60%20%
Philosophers of mind13026%47%12%

Comparing this to some other philosophy subfields, as a gauge of their health:

Groupn  biologicalpsychologicalfurther-fact
Decision theorists1817%67%17%
General philosophers of science5829%55%7%
Normative ethicists12714%46%15%
Philosophers of language12018%38%17%
Philosophers of mathematics1817%61%6%
Philosophers of religion2524%16%44%

Decision theorists come out of this looking pretty great (I claim). This is particularly interesting to me, because some people diagnose the 'academic decision theorist vs. LW decision theorist' disagreement as coming down to 'do you identify with your algorithm or with your physical body?'.

The above is some evidence that either this diagnosis is wrong, or academic decision theorists haven't fully followed their psychological view of personal identity to its logical conclusions.

Regarding "Mind uploading (brain replaced by digital emulation): survival or death?" (adding answers for "the question is too unclear to answer" and "there is no fact of the matter"):

Groupn      survivaldeathQ too unclearno fact
Philosophers (Target)101627%54%5%4%
Phil of computing... (Target)1947%42%11%0%
Decision theorists1242%8%8%17%
Philosophers of cognitive science3735%51%5%3%
Philosophers of mind9134%52%4%2%

From my perspective, decision theorists do great on this question — very few endorse "death", and a lot endorse "there is no fact of the matter" (which, along with "survival", strike me as good indirect signs of clear thinking given that this is a kind-of-terminological question and, depending on terminology, "death" is at best a technically-true-but-misleading answer).

Also, a respectable 25% of decision theorists say "agnostic/undecided", which is almost always something I give philosophers points for — no one's an expert on everything, a lot of these questions are confusing, and recognizing the limits of your own understanding is a very positive sign.

Regarding "Chinese room: doesn't understand or understands?" (adding "the question is too unclear to answer" responses):

Groupn  understandsdoesn'tQ too unclear
Philosophers (Target)103118%67%6%
Phil of computing... (Target)1822%56%17%
Philosophers of cognitive science4434%50%7%
Philosophers of mind9115%70%8%

Regarding "Other minds (for which groups are some members conscious?)" (looking only at the "2009-comparable departments", except for philosophy of computing and information because there aren't viewable results for that subgroup):

(Options: adult humans; cats; fish; flies; worms; plants; particles; newborn babies; current AI systems; future AI systems.)

(Respondent groups: philosophers; applied ethicists; decision theorists; meta-ethicists; metaphysicians; normative ethicists; philosophy of biology; philosophers of cognitive science; philosophers of computing and information; philosophers of mathematics; philosophers of mind.)

 nadult hcatfishflywormplantparticbaby hAIAI fut

I am confused, delighted, and a little frightened that an equal (and not-super-large) number of decision theorists think adult humans and cats are conscious. (Though as always, small n.)

Also impressed that they gave a low probability to newborn humans being conscious — it seems hard to be confident about the answer to this, and being willing to entertain 'well, maybe not' seems like a strong sign of epistemic humility beating out motivated reasoning.

Also, 11% of philosophers of cognitive science think PLANTS are conscious??? Friendship with philosophers of cognitive science ended, decision theorists new best friend.

Regarding "Eating animals and animal products (is it permissible to eat animals and/or animal products in ordinary circumstances?): vegetarianism (no and yes), veganism (no and no), or omnivorism (yes and yes)?":

Groupn          omnivorismvegetarianismveganism
Philosophers (Target)176448%26%18%
Applied ethicists6433%23%41%
Normative ethicists13140%27%31%
Philosophers of mind13448%31%12%
Philosophers of cognitive science7348%29%14%


4. Metaphysics, philosophy of physics, and anthropics

Regarding "Sleeping beauty (woken once if heads, woken twice if tails, credence in heads on waking?): one-half or one-third?" (including the answers "this question is too unclear to answer," "accept an alternative view," "there is no fact of the matter," and "agnostic/undecided"):

Groupn1/31/2unclearaltno factagnostic
Philosophers (Target)42928%19%8%1%3%40%
Decision theorists1354%8%0%15%0%23%
Logicians and phil of logic2836%14%4%7%4%36%
Phil of cognitive science1828%22%6%0%0%44%
Philosophers of mathematics650%17%0%0%0%33%

Regarding "Cosmological fine-tuning (what explains it?): no fine-tuning, brute fact, design, or multiverse?":

Groupndesignmultiversebrute factno fine-tuning
Philosophers (Target)80717%15%32%22%
Decision theorists138%23%23%38%
General phil of science339%21%48%24%
Phil of cognitive science...326%19%50%13%
Phil of physical science1613%25%38%6%

Regarding "Quantum mechanics: epistemic, hidden-variables, many-worlds, or collapse?":

Groupn    collapsehidden-varmany-worldsepistemic
Philosophers (Target)55617%22%19%13%
Decision theorists838%13%63%13%
General phil of science2631%23%27%4%
Phil of cognitive science...166%31%31%19%
Phil of physical science1513%33%33%0%

From SEP:

What is the metaphysical basis for causal connection? That is, what is the difference between causally related and causally unrelated sequences?

The question of connection occupies the bulk of the vast literature on causation. [...] Fortunately, the details of these many and various accounts may be postponed here, as they tend to be variations on two basic themes. In practice, the nomological, statistical, counterfactual, and agential accounts tend to converge in the indeterministic case. All understand connection in terms of probability: causing is making more likely. The change, energy, process, and transference accounts converge in treating connection in terms of process: causing is physical producing. Thus a large part of the controversy over connection may, in practice, be reduced to the question of whether connection is a matter of probability or process (Section 2.1).

Regarding "Causation: process/production, primitive, counterfactual/difference-making, or nonexistent?": 

Groupn       counterfactualprocessprimitivenon
Philosophers (Target)89237%23%21%4%
Decision theorists1471%7%7%7%
Philosophers of cognitive science3858%21%13%5%
Philosophers of physical science1663%19%0%6%

Regarding Foundations of mathematics: constructivism/intuitionism, structuralism, set-theoretic, logicism, or formalism?:

Philosophers (Target)60015%6%12%21%15%
Philosophers of mathematics1513%7%7%40%33%


5. Superstition

Regarding "God: atheism or theism?" (with subfields ordered by percentage that answered "theism"):

Groupn          theism     
Philosophy (Target)177019%
Philosophy of religion2774%
Medieval and Renaissance philosophy1060%
Philosophy of action4221%
17th/18th century philosophy6420%
20th century philosophy3619%
Normative ethics13216%
19th century philosophy2214%
Asian philosophy714%
Decision theory2214%
Philosophy of mind13513%
Ancient Greek and Roman philosophy3113%
Applied ethics6413%
Logic and philosophy of logic7013%
Philosophy of language12812%
Philosophy of social science2711%
Philosophy of law2110%
Philosophy of mathematics2010%
Social and political philosophy10010%
Philosophy of gender, race, and sexuality239%
Philosophy of biology248%
Philosophy of physical science268%
General philosophy of science656%
Philosophy of cognitive science735%
Philosophy of computing and information50%
Philosophy of the Americas50%
Continental philosophy150%
Philosophy of computing and information (Target)250%

This question is 'philosophy in easy mode', so seems like a decent proxy for field health / competence (though the anti-religiosity of Marxism is a confounding factor in my eyes, for fields where Marx is influential).

The "A-theory of time" says that there is a unique objectively real "present", corresponding to "which time seems to me to be right now", that is universal and observer-independent, contrary to special relativity. The "B-theory of time" says that there is no such objective, universal "present".

This provides another good "reasonableness / basic science literacy" litmus test, so I'll order the subfields (where enough people in the field answered at all) by how much more they endorse B-theory over A-theory. Regarding "Time: B-theory or A-theory?":

Groupn          A-theoryB-theorydiff
Philosophy (Target)112327%38%11%
19th century philosophy1331%8%-23%
Philosophy of religion2245%27%-18%
Medieval and Renaissance philosophy933%22%-11%
Philosophy of law1030%20%-10%
Philosophy of social science1724%24%0%
Social and political philosophy4229%33%4%
Philosophy of gender, race, and sexuality1225%33%8%
Ancient Greek and Roman philosophy2124%33%9%
Philosophy of action3129%39%10%
20th century philosophy2223%36%13%
Normative ethics7831%44%13%
Philosophy of cognitive science4918%31%13%
Philosophy of mathematics1712%29%17%
Asian philosophy520%40%20%
Applied ethics2931%52%21%
Philosophy of mind11120%41%21%
17th/18th century philosophy4414%36%22%
Logic and philosophy of logic6128%52%24%
Phil of computing and information (Target)2025%50%25%
Philosophy of language10722%54%32%
General philosophy of science4819%56%37%
Philosophy of biology1619%63%44%
Decision theory1613%63%50%
Philosophy of physical science2612%62%50%

Decision theorists doing especially well here is surprising to me! Especially since they didn't excel on theism; if they'd hit both out of the park, from my perspective that would have been a straightforward update to "wow, decision theorists are really exceptionally reasonable as analytic philosophers go, even if they're getting Newcomb's problem in particular wrong".

As is, this still strikes me as a reason to be more optimistic that we might be able to converge with working decision theorists in the future. (Or perhaps more so, a reason to be relatively optimistic about persuading decision theorists vs. people working in most other philosophy areas.)

(Added: OK, after writing this I saw decision theorists do great on the 'personal identity' and 'mind uploading' questions, and am feeling much more confident that productive dialogue is possible. I've added those two questions earlier in this post.)

(Added added: OK, decision theorists are also unusually great on "which things are conscious?" and they apparently love MWI. How have we not converged more???)


6. Identity politics topics

Regarding "Race: social, unreal, or biological?":

Groupn          biologicalsocialunreal
Philosophy (Target)164919%63%15%

(Note that many respondents said 'yes' to multiple options.)


7. Metaphilosophy

Regarding "Philosophical progress (is there any?): a little, a lot, or none?":

Group                                n            nonea littlea lot
Philosophers (Target)17754%47%42%

Regarding "Philosophical knowledge (is there any?): a little, none, or a lot?":

Group                                n            nonea littlea lot
Philosophers (Target)11104%33%56%

Another interesting result is "Philosophical methods (which methods are the most useful/important?)", which finds (looking at analogous-to-2009 departments):

  • 66% of philosophers think "conceptual analysis" is especially important, 14% disagree.
  • 60% say "empirical philosophy", 12% disagree.
  • 59% say "formal philosophy", 10% disagree.
  • 51% say "intuition-based philosophy", 27% disagree.
  • 44% say "linguistic philosophy", 23% disagree.
  • 39% say "conceptual engineering", 23% disagree.
  • 29% say "experimental philosophy", 39% disagree.


8. How have philosophers' views changed since 2009?

Bourget and Chalmers' paper has a table for the largest changes in philosophers' views since 2009:

As noted earlier in this post, one of the larger shifts in philosophers' views was a move away from moral internalism and toward externalism.

On 'which do you endorse, classical logic or non-classical?' (a strange question, but maybe this is something like 'what kind of logic is reality's source code written in?'), non-classical logic is roughly as unpopular as ever, but fewer now endorse classical logic, and more give answers like "insufficiently familiar with the issue" and "the question is too unclear to answer":


Epistemic contextualism says that the accuracy of your claim that someone "knows" something depends partly on contextual features — e.g., the standards for "knowledge" can rise "as the stakes rise or the skeptical doubts become more serious".

Here, it was the less popular view (invariantism) that lost favor; and the view that lost favor again lost it via an increase in 'other' answers (especially  "insufficiently familiar with the issue" and "agnostic/undecided") more so than increased favor for its rival view (contextualism):


Humeanism (a misnomer, since Hume himself wasn't a Humean, though his skeptical arguments helped inspire the Humeans) say that "laws of nature" aren't fundamentally different from other observed regularities, they're just patterns that humans have given a fancy high-falutin name to; whereas anti-Humeans think there's something deeper about laws of nature, that they in some sense 'necessitate' things to go one way rather than another.

(Maybe Humeans = 'laws of nature are program outputs like any other', non-Humeans = 'laws of nature are part of reality's source code'?)

Once again, one view lost favor (the more popular view, non-Humeanism), but the other didn't gain favor; instead, more people endorsed "insufficiently familiar with the issue", and "agnostic/undecided", etc.:


Philosophers in 2020 are more likely to say that "yes", humans have a priori knowledge of some things (already very much the dominant view):


'Aesthetic value is objective' was favored over 'subjective' (by 3%) in 2009; now 'subjective' is favored over 'objective' (by 4%). "Agnostic/undecided" also gained ground.


Philosophers mostly endorsed "switch" in the trolley dilemma, and still do; but "don't switch" gained a bit of ground, and "insufficiently familiar with the issue" lost ground.


Moral realism also became a bit more popular (was endorsed by 56% of philosophers, now 60%), as did compatibilism about free will (was 59% compatibilism, 14% libertarianism, 12% no free will; now 62%, 13%. and 10%).

The paper also looked at the individual respondents who answered the survey in both 2009 and 2020. Individuals tended to update away from switching in the trolley dilemma, away from consequentialism, and toward virtue ethics and non-cognitivism. They also updated toward Platonism about abstract objects, and away from 'no free will'.

These are all comparisons across 2009-target-population philosophers in general, however. In most (though not all) cases, I'm more interested in the views of subfields specialized in investigating and debating a topic, and how the subfield's view changes over time. Hence my earlier sections largely focused on particular fields of philosophy.


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