It's Only A Theory

Two things on the relationship between science and metaphysics, apropos of the recent discussions on this blog (which I've followed with interest and wish I had more to contribute to):

1. Although I doubt there are many who read this blog who don't already read Leiter's, the recent entry on Jack Ritchie's Understanding Naturalism (and the NDPR review) seems very relevant, and their is a discussion going on in the comments of Leiter's blog.
2. Craig Callender has a draft of a paper on his website called Metaphysics and Philosophy of Science, and I'm sure it would add something to the discussion (and Craig would likely appreciate feedback on it).

Wish I could take the time to say more about these difficult and interesting issues, but it will have to wait, as grading beckons.

Let me articulate what I find problematic about mainstream contemporary metaphysics from the point of view of philosophy that wishes to be scientifically informed and open to learning from and be surprised by science. I will discuss one of the central player of that scene, Ted Sider, and point to its debt in David Lewis.

Sider writes this:
"The ontological realist draws the line in a certain place: part of the world’s distinguished structure is its quanticational [sic--it's a pre-print so maybe not in final version]structure. Those who regard ontological realism as “overly metaphysical” should remember that they too must draw a line.
And in fact, the ontological realist can give a pretty convincing argument
for his choice of where to draw the line. Quine’s (1948) criterion for ontological commitment is good as far as it goes: believe in those entities that your best theory says exists. But in trying to decide how much structure there is in the world, I can think of no better strategy than this extension of Quine’s criterion: believe in as much structure as your best theory of the world posits. The structure posited by a theory corresponds to its primitive notions—its “ideology” in Quine’s (1951) terminology—which includes its logical notions as well as its predicates.
This criterion is as vague..."
http://tedsider.org/papers/ontological_realism.pdf [It's in the Chalmers, Manley volume discussed on this blog recently]

So, the story go like this: in Quine (first order) logic is a) a tool in regimenting our scientific language so that we can generate a perspicuous scheme to articulate or read off our ontology. Moreover, given Quine's linguistic idealism [Jody Azzouni's characterization] (I mean, of course, his semantic holism), logic plays a second role of b) holding together the core of the whole scheme. It's this two-fold function that we may call its "ideology." In principle, Quine is open to whole-scale revolutions of the general web, including giving up standard logic, but these are extremely rare occurrences in principle. (No Carnapian principle of tolerance.)

Now, Sider comes along and says, why separate the underlying logic (quantificational structure) from the scientific theories? All scientific theories have an underlying logic (see the second role of logic in Quine), and we are committed to this. Moreover, this underlying logic captures what David Lewis calls 'natural properties.' So, once one gives up on Quine-ean holism and returns to realism, then there really is no reason to call the underlying logic/quantificational structure an ideology--it just is the way nature is carved up, etc. (Moreover, Seider also seems to argue that having an underlying logic is indispensable to science--I found this argument a bit hazy.)

Sider relies on David Lewis' argument in favor of natural properties, which is really a kind of transcendental argument--if reference is possible the world must have natural properties; there is reference, ergo, future/final scientific language must include natural properties (and, thus, have a classical logic).

If I get this right, then this would explain the general hostility among 'core' metaphysicians to non-classical logics (as I was surprised to discover this during my stay at Syracuse); if pluralism about logic gets a beach-head, then claims about natural properties and shared underlying logic (or a general quantificational structure) don't get off the ground.

So, what's wrong with Sider's view? I can think of six proposals:
i) it throws away Occam's razor unnecessarily. Even if there is an underlying logic, quantificational structure really isn't indispensable in science or in justifying science;
ii) it is dogmatic about logic (in this sense of, can't take alternative logics seriously)
iii) it is dogmatic about (future) science; it can't take conventionalism in science seriously, (and takes the mere possibility of quantification way too seriously);
iva) quantificational structure is too coarse-grained to have any connection with the content of the sciences.
IVb) the sciences don't and won't exhibit natural properties. (Here I am with Ladyman & Ross!).
[iva-b, alternatively claim that Sider's metaphysics is constructed in such a way as to make appeals from science unrewarding.]
ivc) There is a conflict between first-order and second-order axiomatizers, which is the preferred one? [It sometimes seems that Sider's quantificational structures are part of a future, unspeakable language.]
V) Why can't there be non trivial different axiomatizations (constructive, non constructive) of particular sciences? (Start making Cartwright/Dupre style noises.)
VI) Deny that the sciences refer in the way this is understood by Lewis/Sider--argue that science is operationalism all the way down.

No doubt not all of these proposals are equally promising or popular. No doubt Sider and his fans have responses...I want to thank Erik Curiel, Jody Azzouni, Matt Frank, Graham Priest, and Mark Barber for discussing some of these reflections in emails with me this week.

James Ladyman was supposed to give a plenary session (with Anjan Chakravartty) at the most recent BSPS on Tuesday. Sadly he could not deliver it in person; he was ill with swineflu and told to stay at home by authorities; I hope you feel better soon, James!
Steven French was kind enough to deliver Ladyman's talk (which exists as powerpoint slides). It sounded like Ladyman is recanting on some of the crucial issues in chapter 1 of *Every Thing Must* Go (discussed below). (Pressed in Q&A, French said Ladyman "has mellowed".") In particular, I wrote a few weeks ago: "1C: Many of their arguments against far-fetched metaphysics may also be directed at topics in mathematics (the vast majority?) that have no hope of ever being applied to our world. Why can't we be tolerant of a priori metaphysics in the same way we are tolerant of much of mathematics?" To me the new, mature Ladyman agrees with this now. If Ladyman now has a principle of tolerance, much of the polemic bite of the book disappears. Perhaps French misunderstood Ladyman, or I French/Ladyman.
Anyway, I hope to return to my running comments soon.

This Summer I am reading Ladyman & Ross (et al) *Every Thing Must Go: Metaphysics Naturalized* (OUP, 2007) in a reading group with the eminent philosopher of physics, Fred Muller (and hopefully a few others who did not show up for our discussion of the long polemical first chapter) in Amsterdam. Ladyman & Ross are preaching to the choir with us; we enjoyed having a spade being called a spade (surely Kim and Lewis deserve some flack! But why make fun of Andreas Hutteman?). But although we enjoyed the unabashed admiration of Russell, Nagel, and Hume, to our surprise we found plenty of problems with the book. Anyway, perhaps some of my notes may stimulate discussion. I'll number them.
1. (p. 16): The role of mathematics has a funny status in the argument in three ways.
1A: I wonder how L&R view philosophy/metaphysics of mathematics. Is the question, 'what is a number' illegitimate metaphysics? I don't see how it contributes to unification of the sciences, so probably not.
1B: Mathematics is somehow listed with the sciences in contrast to a priori metaphysics. But a large chunk of a priori metaphysics is motivated by developments in (modal) logic. Do L&R tacitly distinguish between mathematics (good) and modal logic (bad)? Do they just deny modal realism? Now while I am suspicious of possible world semantics (etc), what if it turned out to be heuristically fruitful for further developments in modal logic to accept metaphysically robust theses? Should we rule it out?
1C: Many of their arguments against far-fetched metaphysics may also be directed at topics in mathematics (the vast majority?) that have no hope of ever being applied to our world. Why can't we be tolerant of a priori metaphysics in the same way we are tolerant of much of mathematics?
2 (p21): L&R are against abstract composition ("philosophical fetish") and mereology more generally; I applaud them. (I have never understood why folks abandon set theory for mereology.) Yet, given their goal for naturalistic metaphysics (increasing unification/explanation), it looks like they rule out a very promising naturalistic enterprise: creating a taxonomy or classification of "composition relations studied by the special sciences." This does not increase unification, but it might well expose fundamental structural similarities. It is funny that structural realists are blind to alternative ways of doing naturalistic metaphysics.
3 (p22): a nit-pick (or typo). They distinguish between laws of functional interdependence and statements of regularities. Aren't these the same? Perhaps they meant to distinguish between laws of functional interdependence and statements of causal regularities (this is suggested by context).
4 (p23): I am all for criticizing Australian arm-chair naturalistic (physicalist) metaphysics. But is Armstrong really silly for thinking that everything that exists is in space and time? Spacetime may well be emergent from some more fundamental structure, but this is still very much at the level of speculation. It looks like L&R sometimes use the appeal to 'science' or 'physics' to promote controversial and contested views. (A propos, 4B: the criticism of Armstrong is ironic, because L&R spend a lot of time bashing emergentist theories.)
5 (p26): one line of attack on analytic metaphysics is the claim that scientists have no reason to be interested in it (it is often implied that it is embarrassing, laughable, etc). But surely, scientists have no reason to be interested in structural realism either? (Not to mention debates over structural realism!)

Next time more, with special comment on the delicious irony that the enemies of naturalistic metaphysics are bashed for their A-Level chemistry/physics, while the edifice of Ladyman & Ross rests on...a (knowingly) naive sociology of science.

The Leiter Reports is running a poll many of you will have seen on who is the greatest philosopher of the twentieth century. I find it both incredible and appalling that David Lewis makes the shortlist but not Carnap (mind you the list is silly on other grounds too). I always thought I was interested in all areas of philosophy but increasingly I find the questions and methodology of contemporary analytic metaphysics largely uninteresting and ridiculous, and maybe wrongly I blame Lewis' influence for a lot of that. I am interested to know whether my disdain for the way analytic metaphysics is going is shared by many philosophers of science. Or perhaps someone can explain to me why I should care, for example, how many regions of spacetime there are, and why I should think it is the job of philosophers to speculate about such matters.