Nature's things / the nature of things
Ontic Structural Realism vs Ontological Pluralism according to Stephen E. Braude and Hilary Putnam’s last avatar
Thinking, as I have pointed out previously, is by its very nature discrete. It is always about things — individual things or sets of things. A thing is anything that can be the subject of a sentence or proposition composed of a subject and a predicate, and a set is what Georg Cantor, the inventor of set theory, defined as “a Many [i.e., many things] that allows itself to be thought of as a One [i.e., one thing].” This is what makes thinking about time and space so challenging, for neither time nor space is such a “Many.” Where our actual knowledge of self and world is concerned, space is primarily a condition of experience (and thus subjective) and only secondarily a condition of the world as experienced or theoretically constructed by us (and thus objective). And the same goes for time.
Since Cantor, mathematicians have dealt with this situation by transmogrifying continuity into a property that sets can possess. The Standard Model, which is concerned with three fundamental forces (one electromagnetic and two nuclear or short-range), and General Relativity, which is concerned with gravity, and which is our only other empirically well-established physical theory, both represent time and space (or spacetime) as a “Many,” i.e., as a set of instants, points, or “events” (meaning spacetime points). While treating the continuum as a transfinite set has proved to be immensely useful as a feature of calculational tools, reifying or objectifying this feature is a recipe for disaster. Unextended points or instants do not form part of the inventory of the objective world.
In what sense do particles form part of the inventory of the real or objective world? In what sense are they things? In the first part of this post, I will discuss the structural realism propounded by James Ladyman and Don Ross in their provocatively titled book Every Thing Must Go.In the second part I will present Stephen Braude’s thorough inquiry into the nature of things, which turns out to have much in common with the ontological pluralism of Hilary Putnam’s final avatar.
Ontic structural realism
Today, some kind of structural realism is considered by many to be the most defensible form of scientific realism. The ontic structural realism (OSR) propounded by Ladyman and Ross holds that fundamentally relations are all there is: “the attempt to domesticate twenty-first-century science by reference to homely images of little particles that have much in common with seventeenth- and eighteenth-century mechanistic and materialist metaphysics is forlorn.”
The metaphysics of domestication ... seeks to account for the world as “made of” myriad “little things” in roughly the way that (some) walls are made of bricks. Unlike bricks in walls, however, the little things are often in motion. Their causal powers are usually understood as manifest in the effects they have on each other when they collide. Thus the causal structure of the world is decomposed by domesticating metaphysics into reverberating networks of what we will call “microbangings”—the types of ultimate causal relations that prevail amongst the basic types of little things, whatever exactly those turn out to be.... There are, we will argue, no little things and no microbangings.... Indeed, it is no longer helpful to conceive of either the world, or particular systems of the world that we study in partial isolation, as “made of” anything at all. [p. 4]
We of course acknowledge that special sciences are richly populated with individual objects. Thus, to accommodate their elimination from metaphysics we will owe a non-ad hoc account of the point and value of reference to and generalization over objects in sciences other than fundamental physics. We will argue that objects are pragmatic devices used by agents to orient themselves in regions of spacetime, and to construct approximate representations of the world. [p. 130]
By “special sciences” Ladyman and Ross mean not only such fields as chemistry, biology, and economics but also branches of physics like acoustics. Because the special sciences express many if not most of their crucial generalizations in terms of influences from one (more or less) encapsulated system to another, it is hardly possible for them to give up on things qua self-subsistent individuals and their causal relations. Nor do they have to. They have no need for “seeking counterparts to the individuals and processes in fundamental physics” because “fundamental physics merely constrains special sciences.” [p. 290].
What should jump out at us here is the reference to “agents.” As the referrers to things, agents are of paramount importance to the special sciences. On the other hand, being things themselves, they are, like all things, “only epistemological book-keeping devices” [p. 240]. Ontologically, agents are of no import in a philosophy which conjoins eliminativism about self-subsistent individuals with the view that relational structure is ontologically fundamental [p. 130].
One may ask: how is the world’s relational structure implemented or realized? What makes it physical and not merely mathematical? These are questions that Ladyman and Ross refuse to answer: “In our view, there is nothing more to be said about this that doesn’t amount to empty words.... The ‘world-structure’ just is and exists independently of us and we represent it mathematico-physically via our theories” [p. 158]. We? Our theories? How can this be consistent with the view that we (being things) are “only epistemological book-keeping devices”?
This brings to mind Edmund Husserl’s paradox of human subjectivity. The paradox can be stated in the form of a dilemma whose two horns are: (i) the existence of consciousness in the world, and (ii) the existence of the world in consciousness.
The first horn takes the world as the primary reality. In the context of the cognitive sciences, this attitude allow us to gain some understanding of causal chains leading from things out there to firing patterns in brains, but it leaves us stymied by the notorious explanatory gap between neural processes and conscious experience. (Check out Putnam’s comment quoted here.) In the context of OSR, we find ourselves similarly incapable of accounting for the existence of those non-entities who are said to represent the “world-structure” via their theories.
The second horn takes consciousness (at least in the form of human conscious experience) as primary. This attitude allows us to gain some understanding of the general structure of empirical knowledge, its dependence on the logical structure of rational thought and on the spatiotemporal structure of human perceptual experience, but it leaves us stymied by the same explanatory gap approached from the other side. For if the brains studied by neuroscience are themselves objects of perceptual experience, they cannot be the real or ultimate causes of perceptual experience. We are forced not only to recognize our linguistic confinement to object-centric language but also to realize that our physical theories offer us nothing more than correlation laws that obtain between perceptual objects, which can be described in this language. Remove these objects, and nothing remains to be mathematico-physically represented.
Ladyman and Ross are right to reject any reductionistic program that depends on the idea that ultimately “everything comes down to microbanging relationships amongst little things” [196–97]. In the branch of contemporary physics that is known as “particle physics,” objects are generally identified via group theoretic structure. According to Arthur Eddington,
The mathematical theory of structure is the answer of modern physics to a question which has profoundly vexed philosophers.... What sort of thing is it that I know? The answer is structure. To be quite precise, it is structure of the kind defined and investigated in the mathematical theory of groups.
Group theory was first developed in order to mathematically describe symmetries. A symmetry is a transformation of some object which leaves it unchanged in some respects. A square, for instance, has eight symmetries: four rotations, two mirror images, and two diagonal flips. A group of symmetry transformations is a set whose elements can be combined (i.e., performed one after another), such that the result is another element of the group. An abstract group can be represented by a group whose elements are matrices that can be combined by matrix multiplication. The following quotation is from a monographtitled “A Simple Introduction to Particle Physics.” Variations and elaborations of it can be found in most textbooks of particle physics. (If you don’t understand a single word of it, you are not alone.)
What we are going to find is that some physical interaction (electromagnetism, weak force, strong force) will ultimately be described by a Lie group in some particular representation. The particles that interact with that force will be described by the eigenvectors of the Cartan generators of the group, and the eigenvalues of those eigenvectors will be the physically measurable charges. We will find that all force-carrying particles (photons, gluons, W and Z bosons) will be described by the generators of their respective Lie group. The Cartan generators will be force-carrying particles which can interact with any particle charged under that group by transferring energy and momentum, but do not change the charge.... On the other hand, the non-Cartan generators will be force-carrying particles which interact with any particle charged under that group by not only transferring energy and momentum, but also changing the charge.
This characterization is confined to one of three disparate aspects of the modern concept of “particle,” as Brigitte Falkenburg has shown in her outstanding monograph Particle Metaphysics,which I have cited in some of my previous posts. It is rather unfortunate that many theoretical physicists treat this axiomatic aspect, which is exclusively concerned with particle types and their possible interconversions, as if it were all that can be said about the meaning of “particle” in contemporary physics.
Of equal importance is the referential aspect of the meaning of “particle,” which is concerned with the experimental contexts in which individual particles are observed. Agreeing somewhat with the proponents of OSR, Falkenburg stresses that “only the experimental context (and our ways of conceiving of it in classical terms) makes it possible to talk in a sloppy way of quantum objects” [p. 205]:
Quantum concepts refer to the properties of quantum phenomena which occur by means of a given experimental setup.... The carrier of these properties is nothing but the quantum phenomenon itself, say, a particle track on a bubble chamber photograph or the interference pattern of the double slit experiment. [p. 200]
Contra the proponents of OSR, however, Falkenburg insists that subatomic reality is a top-down construct:
Quantum physics investigates nothing but phenomena in a classical environment.... The opposite bottom-up explanation of the classical macroscopic world in terms of electrons, light quanta, quarks, and some other particles remains an empty promise. [p. 339]
The operational aspect of the meaning of “particle,” finally, has been summed up by Wolfgang Ketterle in a popular talk, in which he said that after several years of practice one gets used to “preparing waves and detecting particles.”
So, it’s not building blocks all the way down, but also structure is not all there is. Falkenburg gets it right: “Quantum physics investigates nothing but phenomena in a classical environment.... [C]urrent physics only supports the belief in the existence of quantum processes within a classical world” [p. 339–40, original emphases].
The nature of things
Stephen E. Braude is Emeritus Professor of Philosophy and a former Chair of the Department at the University of Maryland, Baltimore County. He has been president of the Parapsychological Association and Editor-in-Chief of the Journal of Scientific Exploration. He is also a professional pianist and composer as well as the author of seven books. You can find excerpts from three of his books here.
Now consider the following principle:
(P) It is possible to explain why a person S is in mental state m by reference to some corresponding physiological structure or mechanism b identical with, or causally responsible for, m.
(P) is presupposed by identity theorists, epiphenomenalists, and even some dualists. Should it be false, numerous academic disciplines would turn out to have no foundation. To be seduced by (P), one must believe, inter alia, that mental states are certain kinds of things, and that it is possible (at least in principle) to formulate an ontology in which such things as intentional mental states have a place. What Braude argues rather convincingly is that “this general outlook is profoundly and entirely mistaken.... Classes of mental states are simply not neat in a manner amenable to scientific treatment” [ESP205]. Moreover,
unlike those who take this lack of neatness as a characteristic only of our mentalistic vocabulary (or conceptual categories) ... I have been suggesting that this lack of neatness is a fundamental feature of mental phenomena, and that our categories are already somewhat neater than the phenomena to which they apply. When, in the inescapable process of abstraction, we arrive at such categories as remembering (believing, wishing, etc.) that p [i.e., that proposition p states a fact], we inevitably foster the illusion that the range of phenomena under discussion is (in principle) isolable and specifiable — if not by our current stock of categories, then by more adequate future categories.... We tend to forget that the process of abstraction that generates our supply of mentalistic concepts is merely a prerequisite for communication. But there is no reason to suppose a priori that any mentalistic vocabulary is anything more than a communicative tool. In particular, there is no reason to suppose a priori that either our mentalistic vocabulary or the domain to which it applies must be anything more than fuzzy. [ESP 205]
In other words, what makes us think that reality is made up of things and events, is that our thoughts, and therefore our language, and therefore our communications are unavoidably about things, events, or their causal (if–then) relations. The reason this way of thinking is wrong is the underlying assumption “that things or events have a preferred parsing.” [ESP 191] While the word “parsing” usually refers to the process of analyzing a text into grammatical constituents or a string of symbols into tokens, here it refers to something that occurs before there even is a text. It refers to the process by which the “intrinsically undifferentiated flow” [ESP 208] of human experience or behavior comes to be expressed in words or otherwise tokenized.
Things or events do not have a preferred parsing. Nature has no intrinsic structure which it presents to us. Reality is not “a perspective-free warehouse of ontological furniture” [LOI243]. Rather it is we who “parse slices of history in different ways for different purposes” [ESP 204]:
when we recall that inner episodes, bits of behavior, and sentence-tokens have content, meaning, or significance only with respect to the way we position them in a certain parsing of life, and when we recall further that the position of an experience, bit of behavior, etc., with respect to its context is not inherently a clear-cut matter, it becomes ... difficult ... to cling to the view that the domain of the mental — mental states as well as their contents — is anything but fuzzy. The range of possible parsings or descriptions of a context ... is as unlimited as the range of possible perspectives we can take on life itself. There is simply no one correct way (or one context-independent correct way) of positioning an experience or bit of behavior against its context.... (In my view, this difficulty has not been sufficiently appreciated by those who think we can give the meaning of a sentence S in terms of another sentence — for example, one stating the truth conditions for S.) [ESP 205–6]
According to Braude, the meaning of a person’s state or behavior is no more a discrete or in-principle-specifiable thing than (say) the humor of a bit of behavior. The humor of a remark is “positional” in a way that is reminiscent of the contextuality of the properties of a quantum systems. While the latter properties depend for both their meaning and their actual existence on how they are measured or experienced, “the humor of a remark depends on how we position it in its context and on what we bring to our understanding of the context.”
For example, a person’s behavior is seen as humorous when we integrate it in a certain way with its surrounding history. A remark is funny in relation to something that preceded it, though not to any and everything that preceded it. A remark’s humor is a positional property of the remark, not something inherent in it. It is entirely possible that two people A and B regard remark r as funny — but not in exactly the same way — even though we could properly describe them both as having understood the joke. Given A’s history, interests, and his own brand of perceptivity, r might have nuances, overtones, or a kind of complexity and richness that it does not have for B, or even for the joke-teller C, given the different perspectives they bring to the situation. Although these different sets of nuances, etc., are not intrinsic to r, they are also not mere appendages to the (essential) humor of r; indeed, the humor of r is nothing without them.
In fact, there is no essential humor to r, even in just those contexts in which r is funny. First of all, r is funny only in virtue of how we position it in a context; positioned in another way it might not be funny at all. Moreover, since there is an endless number of equally legitimate or correct perspectives, attitudes, etc. that we can bring to our understanding of r, there are endlessly different ways of construing r’s content. Thus, the question “what is the humor of r?” has no single — much less a uniquely correct — answer. Since r has no humor independently of some perspective on its context, and since no perspective is intrinsically preferable to any other, not only is r’s humor not the sort of thing that can be exhaustively specified, it is not even one thing. Certainly, it is not simply a function of any intrinsic features of r.
The same, I would say, is true of the meaning or content of an inner episode or bit of behavior. The meaning or content of what goes on in a person’s mind or of what a person does is, like the humor of r, a positional property of that thing. What the inner or outer episode’s content is depends on the context in which it occurs. But since life does not come pre-parsed for us — that is, since there are many different legitimate ways to characterize any slice of history — any bit of human behavior or human experience may be meaningful in different ways relative to different characterizations of (or perspectives on) its context. So, because experiences and bits of behavior have no content or meaning independently of context and perspective on context, and because no perspective from which behavior and experience are meaningful is intrinsically preferable to any other, this content or meaning is not something our behavior and experience simply have. Like the humor of r, content or meaning is not just one thing, and it is not the sort of thing that can be exhaustively specified.
If we take this seriously, we must construe human history, not as a series of events with a manifest structure or content, but rather as an intrinsically undifferentiated flow of experiencing and behaving that can be parsed and related to one another in various ways, and also reveal different aspects from the points of view associated with these different parsings and positionings. Just as, from the perspective of one such parsing, we can individuate a certain episode and see it as humorous, we can individuate the things people do or experience and view them as significant relative to other things individuated within the same perspective. But since the content or meaning of an inner or outer episode is a positional property and not something it has intrinsically, we must realize that mental states in general are not context-independent elements in the manifest structure of history; there is no such manifest structure. Mental states exist only relative to some parsing and characterization of the flow of life. [ESP 206–8]
The way we can explain identifiable behaviors or behavioral patterns in someone’s life, therefore, is not by locating some activating brain mechanisms or structure. If at all it is possible to explain such things, it is only in a sense that is roughly equivalent to “render intelligible,” and it is only by linking such things with others “so as to form meaningful patterns relative to our present interests.” This, Braude concludes, “may be as far as we can ever hope to push causal explanations of human behavior,” adding that
the idea that all of life and history is an intrinsically undifferentiated flow with an infinite number of aspects (no one of which is absolutely preferable to any other), is rather similar to what mystics have been saying for a long time. But to regard this view as mystical is to miss an important point. The alternative to this position is to say that nature has an intrinsic structure — some built-in division into elements, and that there are fundamental relationships between these elements that their arrangement somehow displays unambiguously. In short, the alternative to this position is really a kind of Tractarian logical atomism.And that, I submit, is a far more fantastic viewpoint than the one I offer in its place. [ESP 209–10]
I ended my post on Hilary Putnam and brains-in-vats by mentioning the ontological pluralism embraced by Putnam’s final avatar. An antithesis (or antidote) to metaphysical realism, ontological pluralism strongly resonates with Braude’s thinking. Metaphysical realists regard the world as possessing a definite character quite independently of our ways of thinking about it. Here is how John Heilsummarizes the antidote:
The concepts we use determine, rather than merely reflect, what is out there, at least in the sense that they determine objects’ boundaries, hence what is to count as an object. It is not that there are no divisions in nature, but that there are too many. Our concepts, or rather systems of concepts, make some of these divisions salient. In saying how the world is, we invoke one or another conceptual system or scheme. Which scheme we invoke depends in part on features of us, our needs and interests. As we learn more and as our needs and interests change, our conceptual schemes evolve.
Suppose this is right. It is then hard to see how we could make sense of talk of a world independent of any conceptual scheme.... We could have no way of describing that world, no way of thinking it: describing and thinking involve representing in terms of a conceptual scheme. Consider a map of the surface of the Earth. We can depict the Earth’s surface by means of a Mercator projection, a Peterson projection, a spherical projection. Imagine someone dissatisfied with these insisting that the Earth be depicted using no projection at all! This is what the metaphysical realist demands for representations of reality in general: a representational system or conceptual scheme that is utterly transparent. But a transparent scheme is no scheme at all....
An everyday description can be wrong; I may falsely believe that there is a desk in my office. But if this belief is false it is not because science tells us that there are no desks (only clouds of particles). Ontology — what there is — is relative to a conceptual scheme.
Just as a conceptual scheme containing desks has its uses, so has a conceptual scheme containing particles or wave functions. But neither has a claim to represent what is “ultimately real.”
Returning to Braude, most scientists would say that at the point where vertical or downward explanation stops, we have reached phenomena that are neither identical with nor causally explicable in terms of still lower-level processes.
At this point we arrive at scientific ground level, where the phenomena are ultimate or primitive in the sense that we can no longer profitably ask of them how they occur. The universe simply works in those ways, and no constitutive processes explain why. So far, this is all quite reasonable. But scientists tend to assume, further, that wherever explanation by analysis finally stops, wherever these fundamental phenomena occur, it will always be on the level of the very small — for example, at the neurological, biochemical, atomic, or subatomic level, and never closer to the surface, at the observable level. [LOI 240]
Braude refers to this position as “the small-is-beautiful assumption,” which he rightly finds “bizarre”:
[Nature] may be characterized on different levels of description, each of which countenances certain things — but not others — as objects, and certain descriptive categories (i.e., predicate and relational expressions) — but not others — as appropriate to those objects. But more important, no one of those parsings or sets of categories is inherently more fundamental than any other. Some may be more appropriate or useful in the context of a guiding set of interests or purposes. But none is justifiable (much less correct) apart from any contextual guidelines. [LOI 240–41]
Once we concede that nature may be characterized at different levels of description, we would expect many of those levels to countenance unique sets of phenomena or regularities — that is, things in nature that are neither reducible to, derivable from, nor capable of being mapped without residue onto, another level of description. For example, it would not be surprising if on the level(s) at which we identify psychological states, there are regularities or phenomena not analyzable at a lower level. In any event, ... one cannot simply assume that psychological descriptions must be further analyzable (e.g., in biochemical or neurological terms, or in the language of physics). It would be more plausible to assume, from the start, that there exists a plurality of irreducible descriptive schemes, each appropriate to a different domain of discourse or range of phenomena. But then we must concede that causal regularities among observable phenomena may not, after all, be further describable or analyzable on a level of description dealing with smaller-scale phenomena.
Or, as Ladyman and Ross would say: “There is no justification for the neo-scholastic projection of causation all the way down to fundamental physics and metaphysics” .
Moreover, since our choice of descriptive schemes can be justified only with respect to a guiding set of interests or purposes, the view that nature has a preferred level of description presupposes that some such set of interests or purposes — some perspective, in other words — is inherently more fundamental, or more concerned with basic questions, than the rest. But that claim is simply incredible. [LOI 244]
J. Ladyman and D. Ross (with D. Spurrett and J. Collier), Every Thing Must Go: Metaphysics Naturalized (Oxford University Press, 2007).
A. Eddington, The Philosophy of Physical Science, p. 146–47 (Cambridge University Press, 1939).
M. Robinson, K. Bland, G. Cleaver, J. Dittmann, A Simple Introduction to Particle Physics, arXiv:0810.3328.
B. Falkenburg, Particle Metaphysics: A Critical Account of Subatomic Reality (Springer, 2007).
S.E. Braude, ESP and Psychokinesis: A Philosophical Examination (1979; revised 2002); while cited page numbers refer to the first edition, some quotes are from the revised edition.
S.E. Braude, The Limits of Influence: Psychokinesis and the Philosophy of Science (1986; revised 1997); here, too, while cited page numbers refer to the first edition, some quotes are from the revised edition.
Logical atomism holds that the world consists of ultimate logical “facts” (or “atoms”) that cannot be broken down any further. Having originally propounded this stance in his Tractatus Logico-Philosophicus, Wittgenstein in his later Philosophical Investigations rejected it. — U.M.
J. Heil, Hilary Putnam, in: A.P. Martinich and David Sosa (eds.), A Companion to Analytic Philosophy (Blackwell, 2001).
'Falkenburg gets it right: “Quantum physics investigates nothing but phenomena in a classical environment.... [C]urrent physics only supports the belief in the existence of quantum processes within a classical world”'
What a nice quote and a fascinating post overall.
Gunther Ludwig's four volume work on the Foundations of Quantum Theory begins with a derivation of quantum theory as describing the set of effects one classical system can have on another without the assumption that one may objectivate those effects, i.e. reconstruct them as being due to some third object "exchanged" between the two. He then reconstructs all of atomic and molecular physics along these lines.
From this we get a nice explanation of why quantum physics uses universal covers of various groups, i.e. SU(2) rather than SO(3) or SL(2,C) rather than the Lorentz group. Since we must use not the rotation group (e.g. SO(3)) but rather the relative orientation group (SU(2)) describing the relative orientations of the classical systems. Gravitation by Wheeler, Misner and Thorne has a similar explanation of SU(2).
Of course we have the notion of particles being explicitly tied to the Lorentz group and thus not clearly surviving acceleration or curved spacetimes. Even more so quarks describe not even classical processes, but a certain algebraic decomposition of classical processes in terms of fictional processes, hence the negative norm to their states.
The complete failure of the bottom up view of the world in quantum theory should really be driven home to students and it's one of the best parts of your book that you do so.