KARL JASPERS FORUM
TARGET ARTICLE 110
NEEDS FOR OBJECTS
29 August 2008, posted 6 September 2008
Review of :
EVERY THING MUST GO - Metaphysics naturalized
by James Ladyman and Don Ross, Oxford University Press.
In : Times Literary Supplement, 22&29 August 2008, pp.31-32
[ I have added paragraph numbers to facilitate discussion - HFJM ]
A book can be important, although its main claims seem to the reader to be as controversial at the end of the book as they were at the beginning. At least, so it seems to me as regards a book of philosophy. And so it is with Every Thing Must Go. By the end, one has learnt a lot about the prospects for establishing the book's very striking claims. But they remain unproven: perhaps inevitable in philosophy, but never mind - enticing work for the future!
The scope is broad. The book's governing question is: what sort of metaphysics should we adopt in the light of natural science ? In answering this question, James Ladyman and Don Ross (helped in some chapters by David Spurrett and John Collier) argue for many claims. Most of these are sophisticated, both in the sense of needing considerable stage-setting in order to be exactly formulated, and in the sense of having judicious, and in some cases subtle, qualifications. The development of these claims also weaves in a good deal of commentary on the recent literature in metaphysics and philosophy of science.
So the book defies simple summary. But if one had to pick out one main claim, it would be that (as the title and subtitle suggest) present-day natural science, especially physics, makes no use of the idea of a "thing" in the sense adopted by most metaphysicians - so that much contemporary metaphysics is deeply wrong. And what is this sense of "thing" ? One main formulation is: there are objects in space-time, each with intrinsic properties, and whose identity and diversity from one another are determined independently of their relations to each other.
This claim is elaborated in four main stages, occupying successive chapters of the book. The first concerns metaphysics; the second, general philosophy of science; the third, the philosophy of physics; and the fourth, the philosophy of the "special" sciences, that is, sciences other than physics. Broadly speaking, it is in the second and third stages that the claim is argued for : it is considerations in the philosophy of science, especially physics, that prompt the denial of objects. The first and fourth stages spell out the consequences, for metaphysics and the special sciences respectively, of there being no objects.
At first sight, the denial of objects seems mad. Surely no fancy argument from the philosophy of science, or of physics, will convince us that there are no people, trees, or rocks ? But of course, our authors are not mad. What they deny is a cluster of philosophical views about objects, which they think are not only traditional and false, but still influential and deeply misleading. Besides, they maintain that once we reject these views and think of objects correctly, as some sort of abstraction from a web of relations, we see that people, trees, or rocks - the objects of everyday life and the special sciences - are just as real as the arcane objects of physics: they are all abstractions from webs of relations. So the upshot of their views is rather the opposite of what you might first guess. They do not deny that everyday thought and the special sciences have a subject matter. Rather, they take the lesson from philosophy of science (especially physics) - the lesson that there are no objects, nor intrinsic properties, prior to relations - to liberate everyday thought and the special sciences from the threat of being in some sense secondary to, or derivative from (or "epiphenomenal" upon) physics. Once we realize that objects are really patterns, each science becomes free to articulate and investigate its own ontology.
So much for the broad picture. I will now say a little about the last three stages, and then concentrate on the first. For although all four stages merit extended discussion, the book's fighting talk about how to do – and how not to do - metaphysics implies that metaphysicians, rather than other philosophers, are the readers most urgently sought.
In the general philosophy of science, the central debate has long been over the view called "scientific realism" : whether successful theories are approximately true, and whether our acceptance of them amounts to belief. Although scientific realism at first sounds reasonable, even platitudinous, there are compelling arguments against it. For example: since we now know that our previous theories, though successful in predicting and explaining phenomena, were false, it is presumably rational to infer by induction that our present theories are false. Twenty years ago, Worrall suggested that the best resolution of the arguments on both sides was "structural realism". Roughly speaking, this is the view that our scientific theories describe the structure of reality, but not the intrinsic natures of objects; and that as science progresses, this structure is described more fully and accurately. In particular, when one physical theory supersedes another, it is typically some structural features of the equations, but not their interpretation, that is preserved.
Ladyman and Ross argue for a cousin of Worrall's position called "ontic structural realism", which holds, roughly, that "structure is all there is" : there are no intrinsic, relation-independent natures of things. The articulation and defence of this position occupies much of the book, and Ladyman and Ross argue that it provides the best resolution of the arguments for and against scientific realism. I shall report just two aspects of this defence - one relating to the philosophy of physics, and one to the philosophy of the special sciences - before focusing on metaphysics.
The philosophy of physics provides two main cases which suggest that, in some sense or other, there are no objects : quantum theory's treatment of indistinguishable particles, and general relativity's treatment of space-time points. Both cases merit a lot of discussion, technically and philosophically. But the leading idea is as follows. In quantum theory, especially quantum field theory, it is wrong to think of particles as individuals : in particular, to try to make sense of "which is which ?" when describing a pair of them, for instance, by assigning quantum states to them. And similarly, in general relativity it is wrong to think of space-time points as individuals in a which-is-which sense. Ladyman and Ross develop and endorse this idea, duly replying to rival positions (including those who distrust the analogy between quantum particles and space-time points). Let me pick out just one strand of the ongoing debate.
One natural objection to ontic structural realism is that relations are impossible without objects that have the relations to each other. To this, the main reply seems to be that objects exist, albeit as "abstractions from relations", or as "relational structures". Thus they cite approvingly Poincare (the inspiration for Worrall's structural realism), who replied to this objection against his structural accroach to geometry, that our need for objects "was but a crutch for our infirmity".
As to the consequences of ontic structural realism for the special sciences (sciences other than physics), I confine myself to the main point : namely, the one I made above, about these sciences' autonomy. Despite the emphasis hitherto on physics, Ladyman and Ross disavow all versions of "reductive" physicalism, and even any special metaphysical primacy for physics. (They do accord it an epistemological primacy, which I will consider shortly.) On the contrary: these sciences' autonomous and lush ontologies - albeit of real patterns, rather than objects as traditionally conceived - prompt them to call their view "Rainforest Realism".
As regards metaphysics, Ladyman and Ross wage two main campaigns. The first is positive, the second negative. The first campaign is to state their conception of "naturalized metaphysics", which is much more specific, both in philosophical doctrine and in its responses to the results of the natural sciences, than most of what today passes for naturalized metaphysics. The doctrine is, roughly speaking, that the job of metaphysics is to provide a unified world-picture : not by reconciling the results of science to everyday or common-sense ideas ("domesticating science"), but by relating scientific theories and hypotheses to each other, and, especially, unifying them. This doctrine is formulated precisely, and defended, as the Principle of Naturalistic Closure ("PNC"): a metaphysical claim is justified solely by its role in showing how two or more scientific hypotheses, at least one of which is drawn from fundamental physics, jointly explain more than the sum of what is explained by the two hypotheses taken separately. That is a mouthful : even more so, when its terms like "scientific hypothesis" and "explain" are given their precise definitions. But Ladyman and Ross do a good job of defending it.
I will pick one aspect of the PNC for further discussion : namely, the special status or role accorded to "fundamental physics". There are two main points here : the second will lead back to the book's main claim, the denial of objects. First, Ladyman and Ross point out that the history of science over the past 200 years provides many examples of the failure of scientific hypotheses that postulate non-physical entities and processes (eg, vitalism in biology); and many examples of corresponding physical hypotheses succeeding (eg, the quantum physical explanation of chemical bonding). This prompts the Primacy of Physics Constraint ("PPC") : special-science hypotheses that conflict with a consensus within fundamental physics should be rejected for that reason alone; while hypotheses in fundamental physics are not symmetrically hostage to the conclusions of the special sciences. Note that this gives physics an epistemological, not metaphysical, primacy. Indeed - and this is my second point - the authors explicitly deny various popular formulations of a metaphysical physicalism. For example, they deny that the physical facts determine all the facts there are (where determination is spelt out in terms of "supervenience", or some kind of causal priority of sufficiency); and even that the physical facts determine all the mental facts; and even that there is some sort of hierarchy of "levels of reality"; and that all causation is physical.
The main reason for these denials lies in Ladyman and Ross's main claim, their denial of objects. More specifically: the versions of physicalism that they reject assume a realm of microscopic objects that, composed with one another, constitute familiar macroscopic objects; and whose causal interactions, by something like collisions and forces as in classical mechanics - "micro-bangings" - constitute the history, or at least the causal history, of those familiar objects. Ladyman and Ross repeatedly deny any such picture, which they derisively call "the philosophy of A-level chemistry" : their reason being that modern science, especially physics, denies it.
So much by way of reporting their first, positive campaign : the statement of how metaphysics should be done. The second, negative, campaign follows in its train. It is to attack as wrong-headed much of metaphysics, as pursued in contemporary analytic philosophy. Here "much" applies both to the subject's content, ie, its methods and results, and to the numerical, sociological fact that many, perhaps most, analytic metaphysicians are allegedly up this gum tree.
As to the methods of metaphysics, there are (at least !) two problems. First, Ladyman and Ross are suspicious of the categories that are the metaphysician's stock-in-trade : both the traditional ones, such as substance and essence, which have been transmitted, and transmogrified, through the centuries since Aristotle; and the modern ones, such as "possible worlds" (whether in the hands of Leibniz or Lewis), mereological composition and supervenience.
Second, they object to the way the metaphysician typically deploys these categories : namely, assessing metaphysical proposals by a cost-benefit analysis, which weighs how well they cohere with common-sense beliefs (sometimes dressed up as "intuitions") and with other, previously endorsed, philosophical proposals. For this procedure is, of course, liable to lead to intellectual conservatism (contrast the fact that in science, the background assumption - surely sensible, as well as virtuous - that our present theory or m model is not completely correct often means that a counter-intuitive result is not rejected, but instead prized as an anomaly that can usefully guide further exploration). And worse than conservatism : it no doubt leads to downright error, when the common-sense beliefs being considered are wrong - which, our authors maintain, they often are. Here we return again to the denial of objects, the rejection of "the philosophy of A-level chemistry". Ladyman and Ross emphasize that their target is especially those metaphysicians who claim to be naturalists in that their views aim to accord with the results of natural science. They say they have no fight with Heideggerians, and other kinds of "philosophical anthropologist" who explicitly reject such an aim.
What should we make of this critique of modern analytic metaphysics ? My own reply has two parts. The first is general and applies equally to similar critiques made by Bas C. van Fraassen and Daniel C. Dennett (which Ladyman and Ross graciously acknowledge). The second part is specific, and leads back to my opening remark that this book leaves plenty of work for the future.
The first reply is the predictable, middle-of-the-road one that any philosopher would give. For any trained philosopher, there are philosophical concepts she accepts (understands - or thinks she does!), and others she rejects or is queasy about. So any philosopher will find some of Ladyman and Ross's objections and arguments telling ("Yes, they are right to reject supervenience formulations of physicalism"), and others wrong or unfair ("What is so suspect about mereology?"). In short: the debate will go on; and - as our authors would agree - rightly so.
My second reply concerns the denial of objects. I agree with Ladyman and Ross that proposals and arguments in contemporary metaphysics often assume, in a casual or cavalier fashion, that some level of microscopic objects, or bottom layer of reality, or supervenience basis, exists, with properties sufficiently like those described in A-level chemistry, to suit the metaphysician's purposes. (Over the years, Mark Wilson has made similar telling criticisms, especially of metaphysicians having an oversimple A-level view of classical mechanics.) But I would have liked much more precision from them about their denial of objects, or - even more! - about their positive conception of objects as abstractions from relations.
Thus, to take the denial of objects, recall the formulation cited above : there are no objects in space-time with intrinsic properties, whose identity is determined independently of their mutual relations. A philosopher trained in modern logic and metaphysics will" immediately ask: what is the meaning of "object" ? Is even the minimal Frege-Quine sense, "referent of a singular term", or "the value of a variable", denied ? And what is the meaning of "intrinsic property" ? Are we to adopt one of the handful of current metaphysical theories of such properties ? And similarly : what exactly does "identity determined independently" mean ? Ladyman and Ross do not answer these questions in any detail, partly because, according to them, a logical framework appropriate for structuralist metaphysics does not yet exist. And perhaps this lacuna is fair enough, especially since their book does so much else. But I hope that they or their fellow structuralists will soon address those questions in full detail - lest the enticing vision, that the world is made of relations "all the way down" prove a mirage.
Senior Research Fellow, Trinity College, Univ. of Cambridge