This past Summer I started a reading group with the eminent philosopher of physics, Fred Muller, and Dutch wunderkind, Victor Gijsbers, on Ladyman & Ross (et all) *Every Thing Must Go: Metaphysics Naturalists*. Recall my earlier postings:
http://itisonlyatheory.blogspot.com/2009/06/notes-to-every-thing-must-go.html
http://itisonlyatheory.blogspot.com/2009/06/more-on-chapter-1-of-every-thing-must.html
http://itisonlyatheory.blogspot.com/2009/07/is-ladyman-recanting.html
Now that I have read about a third of the book, I can make one general positive comment: Ladyman & Ross are very generous toward young scholars; they often cite unpublished papers. They also make a genuine effort to connect their views to figures (historical and present) that share aspects of their views.
Okay, so much for making nice, I will continue with Chapter one by page-number and numbered points (where I left off).
11. (p37) They introduce two important principles (summarized by Fred as follows): i) Principle of Naturalistic Closure (PNC). If with the aid of a metaphysical claim (H) two currently accepted scientific propositions (of which at least one is taken from current physics) explain more than they do separately and without H, then H should be taken seriously. (p. 37) ii) The Principle of the Primacy of Physics (PPC). If a hypothesis from some special science conflicts with currently accepted fundamental physics, then reject it (see also p. 44). Both end up doing non-trivial work in the argument (in what follows it allows them to rule out Davidson's token identity theory, emergentism [which has solid Carnapian credentials!], non-Nagelian reductionisms, supervenience, mereological atomism.
11A: PPC has interesting consequences: a) it makes (fundamental, etc) physics immune from other sciences. Should we want/promote this, and does this make for good metaphysics? At Michael Weisberg's EPSA talk it occurred to me that the practice of Chemistry is massively pressupposing and successfully tacitly testing a theory that has some resemblance to quantum mechanics, but that might be interestingly different, too. (Here's the analogy: 19th century planetary astronomy was creating extremely subtle evidence for lots of differences that make a differences two 'theories' Newton's and Einstein's'.) Why shouldn't we permit future chemistry help us reform physics? b) it rules out a priori competing sciences as fundamental, e.g., Darwinism, information theory, or what we may label, 'Santa Fe' science.
11B: PNC seems to suggest that metaphysics without fundamental physics is not worthy of the name metaphysics. It seems to suggest that asking, what is a "Person?" or "what are rights?" are bogus questions.
12. (p.42): PPC gets argued for based on the history of success in extending and unifying physics in the late nineteenth and early twentieth century. But institutionally (recall it's preferred epistemic proxy), science has really only exploded since the Cold War. So, who knows what science is morphing into now? (Lots of simulations, raw data crunching, and applying physics-alien formal methods to fancy new areas.)
13. (p. 48-52): Nagelian reductions (the deductive explanation of a theory by another theory) are the heroes of L&R's account. This is used to attack functionalism and multiple realization theories in the philosophy of mind. (L&R bite bullets along the way: no natural kinds, p. 51.) This is fun stuff to read; it won't convince anybody working in philosophy of mind (who is not already predisposed to disliking functionalism). I am surprised, for example, that they don't take on the Turingian source for the idea that minds and computers are basically same thing.
14. (p. 51 &53): they make a tantalizing remark about ontology being scale-relative, preventing barriers to identifying referents of different theories. It looks like that their unification project also has some disunity consequences; no special science tokens will have fundamental-physical descriptions (but they promise to address this in chapter 4).
15. (section 1.6): I really liked this section. It argues against all kinds of micro/macro (and mereological) distinctions and the thought that the world comes in 'levels'. (Bill Wimsatt's work springs to mind here.)
Next time, 1.7 and their admission "to being materialist Hegelians" (the synethsis between empiricist and materialist stances).
Your comment that emergentism has "solid Carnapian credentials" puzzled me. He doesn't seem to be an emergentist in "Die Physikalische Sprache als Universalsprache der Wissenschaft," which I always thought was the definitive work to go to for his views on philosophy of mind. Am I ignoring some other important Carnap work (a tragedy I would certainly need to correct!), or do you (perhaps following Ladyman) mean something by emergentism which is different from how I usually understand the term?
ReplyDeleteI have in mind a passage near the end of Carnap's reply in the Schilpp volume devoted to him. (Sadly I could not use books.google to help me find the passage.)
ReplyDeleteHmmm, having trouble figuring out what you could be referring to. I did find something interesting that I hadn't noticed before in the section "Feigl on Physicalism," so I guess I'm glad I went and looked, but that isn't near the end, and more importantly Carnap explicitly rejects emergentism there.
ReplyDeleteThis physics student thinks PPC is ridiculous. And I'm pretty sure other physicists will agree with me here. As Eric points it, PPC prevents other branches of science from reforming fundamental physics.
ReplyDeleteThe underlying problem is that PPC fetishizes the boundaries between various science departments. In fact, those boundaries reflect practical considerations (building telescopes and building organic chemicals require very different skill sets) or historical accidents (a few people who study fluid mechanics work for physics departments, but most draw their pay from math or engineering). Those boundaries do not reflect important epistemic distinctions between fields. Better to just call everything "physics" or "science".
As for PNC, I'm not a fan of giving "explanation" a central role in epistemology, so I'm not going to rely on this strategy to support metaphysical claims.
Aaron, I'll get back to you on Carnap. Can you quote the relevant passage?
ReplyDeleteJacob, yes you state the concerns behind my reservations behind PPC very nicely.
About PNC. In denying 'explanation' a central role in epistemology, you find yourself in a lonely crowd with me. (I view the demand for 'explanation' a kind of theological left-over and not helpful in thinking about scientific practice, but few philosophers are willing to give it up.)
I'm thinking particularly of the very long paragraph which begins on page 883 and ends on page 885; the position is very complicated and subtle (as one would expect), and the interpretation is made somewhat more difficult by the fact that Carnap thinks "emergentism" can have different meanings. Still, the central thesis of paragraph seems to be that the physicalism which Carnap endorses rules out emergentism. Some of the points remind me of Lycan's discussion of what he calls the "two level fallacy" in his book on consciousness.
ReplyDeleteHi Eric,
ReplyDeleteI'm also in the camp that denies explanation a central epistemic role - though I didn't think this was a lonely group - my view is probably mostly a result of being indoctinated by Elliott Sober, who holds a similar skepticism (see, e.g., "Let's razor Occams' Razor" and "Contrastive empiricism" etc.
Chris: good to hear I am not alone! (Kidding aside, blogs like this can reveal/build/inspire communities of like-mindedness.)
ReplyDeleteMy suspicion is that philosophers that know a lot about scientific research are less likely to focus on explanation. (By contrast philosophers who get their science from textbooks or graduate courses in science may find focus on "explanation" natural.)
I like contrastive empiricism, so two cheers for Sober!
(Say hi to the gang at UBC.)
Although I'm sympathetic to the idea that explanation has little to do with epistemology, I don't see how this is an argument against Ladyman and Ross. All they claim is that epistemology is central to metaphysics, and at least in the part of the book I have read, they have not committed themselves to the primacy of epistemology over metaphysics. Explanation might well be the task of metaphysics.
ReplyDeletePNC seems to me highly problematic, but not because it centres on explanation. Much more dubious, in my opinion, is the idea that only science (one human enterprise among many) has metaphysical import.
I do agree wholeheartedly with the criticism of PPC given in this thread.
Where I say that L&R claim "that epistemology is central to metaphysics", I meant _explanation_, not epistemology.
ReplyDeleteVictor I agree and my criticism of PNC did not rely on views about explanation. It looks like we have related criticisms of PNC.
ReplyDelete