Maudlin on the philosophy of cosmology

What’s the difference between a philosopher of science and a scientist who comments on philosophy?  The difference is that the philosopher usually makes sure he’s done his homework before opening his mouth.  I’ve had reason to comment on recent examples of philosophical incompetence provided by Richard Dawkins, Jerry Coyne, Stephen Hawking, and others.  (I’ll be commenting on further examples provided by Peter Atkins and Lawrence Krauss in some forthcoming book reviews.)  In an interview over at The Atlantic, philosopher of physics Tim Maudlin comments on Hawking’s ill-informed remarks about the state of contemporary philosophy.  Hawking and his co-author Leonard Mlodinow claim in The Grand Design that “philosophy has not kept up with modern developments in science, particularly physics.”  The gigantic literature that has developed over the last few decades in the philosophy of physics, philosophy of biology, philosophy of chemistry, and philosophy of science more generally, not to mention all the work in contemporary philosophy of mind informed by neuroscience and computer science, easily falsifies their glib assertion.  Says Maudlin:

Hawking is a brilliant man, but he's not an expert in what's going on in philosophy, evidently.  Over the past thirty years the philosophy of physics has become seamlessly integrated with the foundations of physics work done by actual physicists, so the situation is actually the exact opposite of what he describes.  I think he just doesn't know what he's talking about.  I mean there's no reason why he should. Why should he spend a lot of time reading the philosophy of physics? I'm sure it's very difficult for him to do.  But I think he's just… uninformed.

Maudlin is being too kind, for there is a very good reason why Hawking should make the effort to learn what philosophers are saying.  Hawking and Mlodinow not only pontificate about philosophy in their recent book; the book is itself essentially an attempt to do philosophy of science and metaphysics -- and a very bad one, precisely because they have not bothered to acquaint themselves with the basics of these fields.  Had they done so, they would have saved themselves from committing the egregious fallacies and other errors I and other philosophers have identified in our reviews of the book.  (If a philosopher tried to do physics without first learning what contemporary physics actually says, no physicist would be as generous with him as Maudlin is with Hawking!)

Maudlin has a lot of other interesting things to say, so do read the whole thing.  Commenting on the reasons why contemporary physicists fail seriously to grapple with the foundational philosophical questions raised by their discipline, he says:

[P]hysicists for almost a hundred years have been dissuaded from trying to think about fundamental questions.  I think most physicists would quite rightly say "I don't have the tools to answer a question like 'what is time?' - I have the tools to solve a differential equation." The asking of fundamental physical questions is just not part of the training of a physicist anymore.

and

Look, physics has definitely avoided what were traditionally considered to be foundational physical questions, but the reason for that goes back to the foundation of quantum mechanics.  The problem is that quantum mechanics was developed as a mathematical tool.  Physicists understood how to use it as a tool for making predictions, but without an agreement or understanding about what it was telling us about the physical world.  And that's very clear when you look at any of the foundational discussions.  This is what Einstein was upset about; this is what Schrodinger was upset about.  Quantum mechanics was merely a calculational technique that was not well understood as a physical theory.  Bohr and Heisenberg tried to argue that asking for a clear physical theory was something you shouldn't do anymore.  That it was something outmoded.  And they were wrong, Bohr and Heisenberg were wrong about that.  But the effect of it was to shut down perfectly legitimate physics questions within the physics community for about half a century.  And now we're coming out of that, fortunately.

Notice that even someone who disagreed with Maudlin that Bohr and Heisenberg were wrong to dismiss the need to address the metaphysical issues -- for that is what they were, on his account, essentially doing -- would in the nature of the case be taking a position that physics itself could not justify, a philosophical position.  And if they want to give a rational justification for this position rather than hold it as a mere prejudice, they will of necessity be engaging in philosophical rather than scientific arguments, and thereby implicitly conceding that there is such a thing as rational discourse that isn’t scientific discourse.  The only remaining question is whether to do philosophy well or badly, and those who pretend they are not doing it and scorn those who do are certain to do it badly themselves.  Scientism is self-refuting; or as Gilson famously said, philosophy always buries its undertakers.  

On the “fine tuning” of the universe and attempts to account for it in terms of various “multiverse” hypotheses (on which I’ve had occasion to comment recently), Maudlin remarks:

If we give up on that, and it turns out there aren't these many worlds, that physics is unable to generate them, then it's not that the only option is that there was some intelligent designer.  It would be a terrible mistake to think that those are the only two ways things could go.

I think he’s right about that.  Both atheists and some theists attribute an importance to this issue that it simply doesn’t have.  It is as foolish for theists as it is for atheists to make too big a deal of what current physics has to say about this or that, whether it’s “fine tuning,” multiverse theories, or whatever.  That’s “god of the gaps” (or “No god of the gaps”) territory, and it has nothing to do with natural theology as its greatest practitioners understood it, or as a serious atheist should understand it.  Natural theology, as I have argued, rests on deeper considerations than natural science -- considerations that any natural science must itself take for granted -- and thus on considerations that are unaffected by the current state of play in natural science.

Maudlin also makes some astute remarks about the relevance of contemporary physics to the philosophy of time:

Some physicists are very adamant about wanting to say things about [time]; Sean Carroll for example is very adamant about saying that time is real.  You have others saying that time is just an illusion, that there isn't really a direction of time, and so forth.  I myself think that all of the reasons that lead people to say things like that have very little merit, and that people have just been misled, largely by mistaking the mathematics they use to describe reality for reality itself.  If you think that mathematical objects are not in time, and mathematical objects don't change -- which is perfectly true -- and then you're always using mathematical objects to describe the world, you could easily fall into the idea that the world itself doesn't change, because your representations of it don't.

“Mistaking the mathematics they use to describe reality for reality itself” -- now there’s the fallacy of scientism in a nutshell.  Not that this entails that the mathematics does not describe the reality at all; the point is that it does not give us an exhaustive description of reality, but is rather an abstraction from a reality that in itself is richer than can be captured by mathematics alone, even in principle.  (Nor do proponents of scientism ever give non-fallacious arguments for thinking otherwise -- here’s one example.)

The claim that physics has shown that change is illusory is in any event seriously problematic.  As Karl Popper noted, Einstein, as interpreted by Minkowski, recapitulates Parmenides.  (See the essay “Beyond the Search for Invariants” in Popper’s book The World of Parmenides.)  And that means that relativity, if interpreted as entailing the illusoriness of all change, would inherit all the problems with Parmenides’ position.

Now I don’t myself believe for a moment that modern physics really has shown that there is no genuine change in the external physical world.  But even supposing for the sake of argument that it has, that would not show that all change is an illusion, for two reasons.  First, what we would have in this case is one more instance of the common strategy whereby science (as the moderns have defined “science”) attempts to unify phenomena by relativizing the apparent differences between them to the observer.  Hence “heat,” “sound,” “red,” “green,” etc. are redefined so that what common sense means by these terms (features which are irreducibly qualitative rather than quantitative, and which can vary from perceiver to perceiver) is relativized to the “mental” or “subjective” point of view of the observer, and what is allowed to count as “objective” or “physical” heat, sound, or color  is only what can be captured in a quantitative model -- the motions of particles, compression waves, surface reflectance properties, and the like.  So too, time and change, when treated as if they do not really exist in the external world, are relativized to the mind of the observer as mere projections onto external reality.

But the observer himself remains.  And as Popper pointed out, there is no getting around the fact that change really occurs at least within the observer’s consciousness itself.  To deny this is implicitly to deny the very empirical evidential base on which physical theory is supposed to rest.  (Democritus’ paradox all over again.)  Hence if Einstein really were Parmenides redevivus, his position would face incoherence just as the Eleatic philosopher’s did, at least if the Minkowskian interpretation is correct and if we want to say that the conscious subject is a part of a natural world that is purportedly free of change.  Alternatively, we could adopt a dualist view according to which the conscious subject is not a part of that world.  That will save the Minkowskian view from incoherence, but at the cost of merely relocating change rather than eliminating it.  (And also, of course, at the cost of leaving us with the problem of explaining how the conscious subject is related to the natural world if it is not part of it.)

A second point is that unlike Parmenides’ own block universe, the block universe of Minkowski is supposed to be governed by laws that are contingent.  And if they are contingent, then, the Aristotelian-Thomistic philosopher will argue, they are merely potential until actualized.  That means that even if there were no real change or actualization of potency within an Einsteinian four-dimensional block universe, the sheer existence of that universe as a whole would involve the actualization of potency, and thus something like change in the Aristotelian sense (and thus in turn an actualizer or “changer” distinct from the world itself, though that’s a subject of its own).

Anyway, the occasion of the Atlantic interview with Maudlin is the advent of philosophy of cosmology as a distinct subfield within philosophy of physics.  This is a welcome development, which will hopefully bring some sobriety to a discussion to which the likes of Hawking, Krauss, and others have been contributing so many silly and ill-informed remarks.  Here’s an appropriate video to watch in celebration.  (Just for laughs, you might think of the giant squid head as representing the dark forces of vulgar scientism, and the Beasties and their robot as striking back in the name of true, philosophically-informed science.  Have fun!)