Physicists Should Stop Saying Silly Things about Philosophy

The last few years have seen a number of prominent scientists step up to microphones and belittle the value of philosophy. Stephen Hawking, Lawrence Krauss, and Neil deGrasse Tyson are well-known examples. To redress the balance a bit, philosopher of physics Wayne Myrvold has asked some physicists to explain why talking to philosophers has actually been useful to them. I was one of the respondents, and you can read my entry at the Rotman Institute blog. I was going to cross-post my response here, but instead let me try to say the same thing in different words.

Roughly speaking, physicists tend to have three different kinds of lazy critiques of philosophy: one that is totally dopey, one that is frustratingly annoying, and one that is deeply depressing.

  • “Philosophy tries to understand the universe by pure thought, without collecting experimental data.”

This is the totally dopey criticism. Yes, most philosophers do not actually go out and collect data (although there are exceptions). But it makes no sense to jump right from there to the accusation that philosophy completely ignores the empirical information we have collected about the world. When science (or common-sense observation) reveals something interesting and important about the world, philosophers obviously take it into account. (Aside: of course there are bad philosophers, who do all sorts of stupid things, just as there are bad practitioners of every field. Let’s concentrate on the good ones, of whom there are plenty.)

Philosophers do, indeed, tend to think a lot. This is not a bad thing. All of scientific practice involves some degree of “pure thought.” Philosophers are, by their nature, more interested in foundational questions where the latest wrinkle in the data is of less importance than it would be to a model-building phenomenologist. But at its best, the practice of philosophy of physics is continuous with the practice of physics itself. Many of the best philosophers of physics were trained as physicists, and eventually realized that the problems they cared most about weren’t valued in physics departments, so they switched to philosophy. But those problems — the basic nature of the ultimate architecture of reality at its deepest levels — are just physics problems, really. And some amount of rigorous thought is necessary to make any progress on them. Shutting up and calculating isn’t good enough.

  • “Philosophy is completely useless to the everyday job of a working physicist.”

Now we have the frustratingly annoying critique. Because: duh. If your criterion for “being interesting or important” comes down to “is useful to me in my work,” you’re going to be leading a fairly intellectually impoverished existence. Nobody denies that the vast majority of physics gets by perfectly well without any input from philosophy at all. (“We need to calculate this loop integral! Quick, get me a philosopher!”) But it also gets by without input from biology, and history, and literature. Philosophy is interesting because of its intrinsic interest, not because it’s a handmaiden to physics. I think that philosophers themselves sometimes get too defensive about this, trying to come up with reasons why philosophy is useful to physics. Who cares?

Nevertheless, there are some physics questions where philosophical input actually is useful. Foundational questions, such as the quantum measurement problem, the arrow of time, the nature of probability, and so on. Again, a huge majority of working physicists don’t ever worry about these problems. But some of us do! And frankly, if more physicists who wrote in these areas would make the effort to talk to philosophers, they would save themselves from making a lot of simple mistakes.

  • “Philosophers care too much about deep-sounding meta-questions, instead of sticking to what can be observed and calculated.”

Finally, the deeply depressing critique. Here we see the unfortunate consequence of a lifetime spent in an academic/educational system that is focused on taking ambitious dreams and crushing them into easily-quantified units of productive work. The idea is apparently that developing a new technique for calculating a certain wave function is an honorable enterprise worthy of support, while trying to understand what wave functions actually are and how they capture reality is a boring waste of time. I suspect that a substantial majority of physicists who use quantum mechanics in their everyday work are uninterested in or downright hostile to attempts to understand the quantum measurement problem.

This makes me sad. I don’t know about all those other folks, but personally I did not fall in love with science as a kid because I was swept up in the romance of finding slightly more efficient calculational techniques. Don’t get me wrong — finding more efficient calculational techniques is crucially important, and I cheerfully do it myself when I think I might have something to contribute. But it’s not the point — it’s a step along the way to the point.

The point, I take it, is to understand how nature works. Part of that is knowing how to do calculations, but another part is asking deep questions about what it all means. That’s what got me interested in science, anyway. And part of that task is understanding the foundational aspects of our physical picture of the world, digging deeply into issues that go well beyond merely being able to calculate things. It’s a shame that so many physicists don’t see how good philosophy of science can contribute to this quest. The universe is much bigger than we are and stranger than we tend to imagine, and I for one welcome all the help we can get in trying to figure it out.

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225 Responses to Physicists Should Stop Saying Silly Things about Philosophy

  1. Pingback: Physicists And Philosophy | Transterrestrial Musings

  2. Reinaldo Ramos de Carvalho says:

    Thanks Sean for putting in very clear words such an important subject, especially for graduate students. Those who don’t value philosophy of science should read “Representing and Intervening” by Ian Hacking.

  3. Merle Riley says:

    This comment is in memory of an old philosopher friend of mine, Robert Weingard, who passed away too young several years ago. I too am a philosopher (except a PhD in science from “MIT west”). I generally agree with Hawking and Tyson, their points are obvious. I would add that philosophy can find a just location in the areas of physics that lie just beyond the accepted areas of current knowledge. Of course that is vague too, and raw material for further verbosity. Would you rather have a philosopher or physicist answer the question, “Am I worthwhile?”

  4. Dustin Summy says:

    I agree that philosophy has important contributions. I think it’s important to sit down and think through questions like “Does the way we’re talking about X really make sense given Y?” Daniel Dennett has given me a much better appreciation of philosophy’s utility for framing questions. I don’t think people roundly disparaging philosophy realize that philosophy is not just “Am I a brain in a vat?”

    My question for you, because I go back and forth on this all the time: Are the stereotypical, face-palm-inducing questions that these physicists are thinking of when they say these things useful? I mean, are they at least correct about something or are they just philistines through and through? (Or am I being too philosophical? 😛 )

  5. Shmi Nux says:

    As I said in the link to this post on Less Wrong, “philosophy is great at asking interesting questions but lousy at answering them. Typically, an interesting answer to a philosophical question requires first recasting it in a falsifiable form, so that is becomes a natural science question, be it physics, cognitive sciences, AI research or something else… Philosophical questions do not have philosophical answers.”

  6. Shodan says:

    Completely agree with the above. But for posterity, here’s an essay on Philosophy by Stephen Weinberg.

  7. Philosopher says:

    Excellent! I think that those critics dont know too much about contemporary philosophy.
    There are absolutely brilliant philosophers of physics, e.g, John Earman, Jeremy Butterfield, Tim Maudlin; philosophers of science, e.g, Bas Van fraassen, Patrick Suppes, Paul Thagard; and even metaphysicians, e,g, David Lewis, Ted Sider, John Hawthorne, Peter Van Inwagen, etc.

  8. Carl 'SAI' Mitchell says:

    Science is very good at providing models of HOW things work. Physics does that in incredible detail. Science is terrible at providing explanations of WHY things work. Science observes nature, creates predictive mathematical models from the observations, and uses those models to explain the how. It never gets into why the models are the way they are, except when they depend on deeper models (eg statistical mechanics explains why the laws of thermodynamics work as they do).

    We’ll never have scientific proof of the answers to untestable questions, but philosophy can discover the possible answers and allow reasonable choices to be made when the questions are important. It won’t always tend towards an objective truth, but it seems to have done reasonably well so far at illuminating the questions.

  9. Melvin Ely says:

    One of my favorite Teaching Company courses (besides the two which you have done!) is Jeffrey Kasser’s “Philosophy of Science”. This course, for me anyway, brings the two disciplines nicely together.

  10. John Hamill says:

    Is there perhaps a hint of a straw man here? These aren’t the three ‘criticisms’ I’ve heard Krauss et al make, if they can be called criticisms. Specifically, the view of some physicists that seems to have generated controversy is that philosophers don’t find out new things about the world. Philosophers may be very valuable in helping to explain what someone else has found out … but this seems to be a different point to the three described above.

  11. Carl Pham says:

    I think philosophers have become too afraid of the physicists, which leads to either obsequiousness or ignorant hostility. One and even two and three hundred years ago, when physics was upending the naked-eye view of how the world worked, the physicists were much more attentive to the problem of how do you know what you know and what you don’t, and more open to wildly creative (if usually wrong) synthetic concepts. They knew they were swimming against the current in the philosophers’ world. The opposition made them sharp.

    Now, unfortunately, it’s the other way around. The philosophers — including all of us, individually, struggling to set our own philosophy, if we are not mindless hedonists like so many — are swimming in the current of physics. We frame our worldview assuming the crassest implications from cosmology and quantum mechanics, say, are The Final Truth. But it may not be. It has often been the case before that the Final Truth of the natural philosophers has turned out to be less final than initially thought. We should all be pushing a little harder at what physics tell us, or thinks it tells us: how do you know that? What are your confidence limits? Examine your reasoning carefully for hidden unexamined assumptions, cognitive biases, logical leaps. The philosophers should be pushing the physicists to do the same thing, too.

    It concerns me that there seems to be less debate on foundational ideas than there used to be: Boltzmann contended with those who did not believe in atoms. To be sure, they were wrong, but their doubt was intellectually respected, and it forced the atomists to sharpen up. Where are the doubters of today? We all mock Einstein for doubting that God rolls dice, but it bothers me that there isn’t some heir that thinks QM is so much contrivance, a Rube Goldberg way of getting at something that a cleaner theory would point to without one needing to believe six impossible things before breakfast. Even if such people turned out to be wrong, we need them to sharpen up, to continue to make progress.

    What’s Wilson Mizner’s famous quote? “Doubt is what gets you an education.” We need more doubt, and philosophers are the original vendors of doubt.

  12. Ben Goren says:

    First, I would make clear that there are people who call themselves, “philosophers,” who have made and continue to make significant contributions to the body of human knowledge.

    But I would then argue that philosophy as a discipline is as useless and outmoded as alchemy and astrology.

    And the reason for that is that the only meaningful dividing line that can be drawn between the two is that of empiricism. Philosophy itself has no requirement that philosophy is grounded in that which has been or could be observed; science is nothing without objective analysis.

    When we see good work coming out of people who call themselves, “philosophers,” that work is “merely” an analysis or meta-analysis of hard facts gathered by one or many researchers. But, all too often, we also see philosophers completely ungrounded by reality going off on wild flights of fantasy.

    The perfect example is morality, which is supposed to be one of philosophy’s great strengths. When actually scientists (by whatever title) study morality, they do so either with hard research, such as patient outcome surveys, or with solid math, such as game theory. But when philosophers “study” morality, they do so with nonsense such as the Trolley Car Death Fantasies, which anybody who made it through a psychology class for non-majors should instantly realize as nothing more than a watered-down variation on Stanley Milgram’s famous experiment. The philosopher, wearing the lab coat of authority, tells the subject to either kill the ugly fat man or the beautiful woman, and the subjects invariably comply, exactly as Milgram demonstrated they would. In the real world, such scenarios simply don’t arise, and, when they do, either the person at the switch has no business touching critical industrial safety infrastructure in a crisis situation or the person is a trained professional and has drilled in exactly what procedure to follow — and, either way, the fault for the deaths lies with whoever permitted such a dangerous situation to arise in the first place, not the unlucky person who stumbled upon the scene.

    We see similar parallels with all the other fields which philosophy is supposed to dominate: scientists are discovering the true nature of those problems while the philosophers are “not even worng.” Quantum mechanics such as you yourself, Sean, have done far more to determine the ultimate nature of reality than any philosopher, and no philosopher will ever contribute to that question without a solid grounding in all the latest research. The nature of life was settled long ago by scientists. Information theory has turned the nature of knowledge into a settled question. And so on — again, all without any appeal to philosophy whatsoever. Even the philosophy of science is a matter for the empiricists to analyze: which peer review model produces the papers that have the fewest mistrakes and the most utility for others?

    Again, I appreciate that there are people who call themselves philosophers who do good work. But, whatever the labels on their hats say, those hats are scientific hats, not philosophical hats — at least, when they’re actually being productive.



  13. Anon says:

    I think the job of a philosopher is a pointless one in a certain sense. There is nothing that a philosopher can do that a good physicist cannot. However, that assumes that the physicist actually cares and tries to understand what everything means instead of just being an equation manipulator.
    The philosophy of physics (space, time, etc) is the foundation of physics and has very real consequences for how we think about unsolved problems. Any physicist who doesn’t appreciate that fact is simply a fool.

  14. Dwt says:

    Paraphrasing Neils Bohr:
    What is the difference between a [physicist] and a philosopher? An [physicist] is someone who starts out knowing something about some things, goes on to know more and more about less and less, and ends up knowing everything about nothing. Whereas a philosopher is someone who starts out knowing something about some things, goes on to know less and less about more and more, and ends up knowing nothing about everything.”
    Buddhism and Taoism assert that nothing and everything are two sides of the one coin which is Reality. Bohr incorporated the Taoist yin/yang symbol is his self designed coat of arms along with with the motto “CONTRARIA SUNT COMPLEMENTA”
    My conclusion is that physics and philosophy are not mutually exclusive, but mutually dependent in the pursuit of understanding of reality and truth, which are also two sides of one coin.

  15. Lord says:

    Under which does the criticism philosophy seems to be about torturing word definitions fall?

  16. Simon Morley says:

    Your broad minded approach is both very refreshing, and a welcome boost to science. Do you mind if I test it?
    Regarding, for instance, your notion of the Arrow of Time.
    If you don’t know what time is (and knowing is binary – you either know what time is or you don’t, phrases like “we know quite a lot about time” don’t count) how then can you assert that it has a direction? Your notion is based entirely on the empirical evidence of event outcomes. It has nothing to do with time (other than time, the abstract framework, calibrates and indexes these events). You are making an assertion about something you admit to not fully understanding.
    Time is an abstract. We know this because there is no empirical evidence that it exists, none. You can’t see it, hear it, touch it, smell it. It doesn’t make anything, move anything or destroy anything. It’s hence abstract.
    (If space-time is a viable construct of two separate paradigms, they need to be paradigms of compatible nature. So if time is an abstract framework, then for space and time to fuse, the version of space being assimilated into space-time must also be an abstract framework. And the resultant mix, space-time, must hence be an abstract framework).
    The only empirical evidence of “time passing” are events. And events are caused by energy differential (not by time).
    If time is abstract, how can it have a direction?
    Surely the arrow belongs to the outcome of events. Shouldn’t your notion be called “The arrow of event outcomes?” It makes a big difference – else you are implying a property to time that you simply can’t support.

  17. “Philosophy tries to understand the universe by pure thought, without collecting experimental data.”
    I love this criticism because, c’mon, theoretical physics?

    “Philosophy is completely useless to the everyday job of a working physicist.”
    I have a *little* more sympathy for this criticism, because there are other assumptions going into it: that Philosophy of Physics is trying to be useful to understanding the physical world, but is not. Sure, it’s interesting in the same way that a book or a poem is, but not in the way that science is; rather, it’s telling us how our minds interpret the world, not how the world IS. (To be clear: I think this is what the underlying argument is, not that I agree with it.)

    We all have a limited set of intellectual interests; for some people it really is just, “how the physical world can be described”.

    “Philosophers care too much about deep-sounding meta-questions, instead of sticking to what can be observed and calculated.”
    Honestly, your attack on this is way off base. There is clearly a strong empirical tradition that physicists are appealing to in this case. It is very easy to mislead oneself about how the world works when just *thinking* about it (see also: most of human history), and much harder when “getting data”. Disagree with it all you want, but that’s a firm philosophical position.

    tl;dr The broader problem here is that scientists have very strong philosophies, they just don’t realize it or think them through properly. Give them examples that they care about or you’re just saying, “I think this is interesting and you should too.”

  18. Joan Hendricks says:

    Gotta say, Dr. Carroll, I read both of your recent books and learned a lot from them about Higgs and Particle at the End of the Universe. Then, I tried to read Tim Maudlin’s book that you recommended (can’t remember the name of it). I gave up less than halfway through. Philosophy is not my thing I guess.

  19. Steve Jones says:

    I suppose somebody might point out the irony that those who are indulging in a debate about physics and the value of empiricism as the true test of knowledge of the universe are, of course, taking part in a philosophical discussion. You might also argue that mathematics and logic are in the realm of philosophy as they rather stand outside the world of empiricism. Where would physics be without mathematics and logic?

    However, it’s also worth noting that there’s a huge range of stuff that falls under the term philosophy. Some of the traditions of philosophy are wildly different from those that are closely related to physics.

  20. Mina says:

    Thanks for sharing this. But what is the criteria to distinguish between a philosophical question and a scientific question? Why is “the arrow of time” a philosophical question and not a scientific one?

  21. Alan Cooper says:

    Some of the best philosophers have been at least as critical of “philosophy” as the most strident of physicists. And some of the seemingly objectionable quotes from physicists come in response to the loud claims by some (often unemployed) philosophers that we “need” their expertise for some reason or other. Although I enjoy and see value in the study of how our understanding of various “deep” questions has evolved (or not) over time, I do not need the advice of a professionally trained philosopher to help me decide even moral questions – let alone issues of natural philosophy. In my opinion, the discipline of philosophy would be better served by an attitude common among my mathematical physics colleagues – namely pride in the belief that what we do is “useless” from a crudely materialist perspective but still of great aesthetic value to those who appreciate it.

    P.S. I don’t think it was fair to elide “completely useless” into “uninteresting or unimportant”. And the most famous comment re usefulness was in fact (intentionally?) open to a wide range of interpretation since many species of birds would now be extinct but for the interest of ornithologists (even though those birds need neither ornithologists (nor aerodynamicists) in order to actually fly).

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  23. Ben Goren says:

    I suppose somebody might point out the irony that those who are indulging in a debate about physics and the value of empiricism as the true test of knowledge of the universe are, of course, taking part in a philosophical discussion.

    Theologians are also wont to claim all of science as a sub-discipline of theology, as it’s all for the greater glory of whichever gods the theologian worships. I remain underwhelmed by both assertions.

    Regardless, the question is an entirely empirical one. In what ways has knowledge been advanced with empiricism (science, broadly construed) and without (philosophy)? The scorecard is so overwhelmingly in favor of science it’s a wonder we’re even having the discussion.



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