More on Science and Metaphysics

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.

David Lewis and Newton's Challenge, (or the relationship between science & metaphysics)

By "Newton's Challenge," I refer to the fact that after the Principia’s success the authority of "science" has been used to settle debates within "philosophy." I distinguish among three different but closely related versions of this challenge: (NC1) a philosopher claims that natural philosophy must be consulted in the process of doing metaphysics; (NC2) a philosopher claims that natural philosophy is epistemically prior to metaphysics; (NC3) a philosopher appeals to the authority of a natural science, which is in some sense (institutionally, methodologically) taken to be a non-philosophical source, in order to settle argument over doctrine. Much of my recent scholarship focuses on tracing out the development and crucial role of Newton's Challenge in the history of philosophy and science.

Sometimes "Newton's Challenge" gets resisted by philosophers. Here's an interesting and prominent example:

"...maybe the lesson of Bell's theorem is exactly that there are physical entities which are unlocalized, and which therefore might make a difference between worlds--worlds in the inner sphere--that match perfectly in their arrangements of local qualities. Maybe so. I'm ready to believe it. But I am not ready to take lessons in ontology from quantum physics as it now is. First I must see how it looks when it is purified of instrumentalist frivolity, and dares to say something not just about pointer readings but about the consitution of the world; and when it is purified of doublethinking deviant logic; and--most of all--when it is purified of supernatural tales about the observant mind to make things jump. If, after all that, it still teaches nonlocality, I shall submit willingly to the best of authority."--David Lewis Philosophical Papers, V2, introduction xi

Given the way I have formulated "Newton's Challenge," I just love Lewis' terminology ("submit," "authority"," "lessons in ontology," etc.)!
In a fascinating recent plenary lecture at BSPS in Norwich, Simon Saunders claimed that with the theory of decoherence, Quantum Mechanics now meets Lewis' challenge. If Saunders is right then philosophers of science have a club to beat the metaphysicians.

Is Ladyman recanting?

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.

Notes to Every Thing Must Go

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.