Modal Problems with the Theory of Powers

This is the last of four posts prompted by my reading of George Molnar’s Powers: A Study in Metaphysics.

While in previous posts I quibbled with some of the ontological details of Molnar’s theory, I think there are bigger problems which ultimately undermine his approach. These problems center on modal issues. On the one hand, the positing of necessary connections between powers and manifestations to explain causality is too easily rejected by the adherents to a Humean view. On the other hand, from the perspective of a reader sympathetic to causal realism, the theory has the wrong modal structure to support an asymmetric causality which matches our intuition. At the end of the post, I argue that the recasting of powers as propensities can lead to a superior theory.


The theory of powers is motivated by a desire for causal realism. The alternative Humean view is that causality has no mind-independent reality: the world has regularities, but not causation. Now, the nature of a power is only revealed by its manifestation. For this reason, Molnar explains that it is a feature of the theory that the connection between a power and its manifestation is a necessary one. Hume, at least in the usual modern interpretation, denied the existence of necessary connections between distinct things (recall a power is distinct from its manifestation, since it can exist in the absence of the manifestation). While Molnar argues that Hume’s dictum can be rejected, as it ultimately leads to an overly corrosive skepticism, many philosophers would apply the dictum in this case. It’s especially easy to see this for those who would take a four-dimensional block perspective on the universe as a model. How would the events in the block universe alter if we removed these necessary causal connections? The answer is not at all. So, the ontologically sparser view is deemed superior.

But of course, the block universe model implies there is no mind-independent asymmetric causal flow in nature. If the theory of powers can help us explain the kind of “real” causation which matches our intuitions, shouldn’t we endorse it?

Well, by my reading, Molnar’s theory of powers doesn’t achieve this goal. The asymmetry of causality means the past is fixed while the future is open (please note I’m not committing to a global evolution in conflict with relativity). Molnar doesn’t have the right modal structure for this asymmetry. For a given causal past (which is determined), we need to explain what happens next (which is undetermined). To recap the theory, there are necessary connections between powers and manifestations; also, recall that powers actually exist, and do so even when not manifested. So how does this explain the fact that manifestations sometimes occur and sometimes don’t? How can a necessary connection give us a possible manifestation?

Molnar explains that the causal effects we normally think about are actually complex conjunctions of power properties and some non-power properties. This can explain the apparent existence of indeterminism in our perception. But at the mind-independent fundamental ontological level, there doesn’t seem to be any basis for indeterminism in the theory.

I think the solution would be to sacrifice the actuality of powers and turn them into propensities. I’m defining a propensity to be a power which is a possibility. A manifestation event is the actualization of such a possibility. Molnar considers this idea very briefly and rejects it in just a couple of paragraphs. He evidently takes it as a given that something which is “merely” possible cannot enter into causality.

The ontological cost of admitting causally relevant possibilia seems high to many. We need to replace the traditional ontological division between the “actual” and the “merely possible” with a modal realist vision which admits a role for possibilities which are “real” enough to enter into causal relations and be actualized. The specific combination of power/propensities and/or other kinds of properties needed to achieve an actualization event can be worked out in more than one way. Gregg Rosenberg’s theory is a recent one which features this kind of modal realism. In his model of causation, two types of properties (effective and receptive) are needed for actualization. Jennifer McKitrick recently reviewed Rosenberg’s book and offered detailed comments on his model of causation. While her criticisms were often perceptive and thought-provoking, she also had (in my opinion) a surprisingly hard time grappling with this sort of modal realism.

I think if you really want a satisfying treatment of causality, you need to have this modal dimension. The nice thing about it is that it neatly matches the best (IMO) interpretation of quantum mechanics!

P.S.
For a critique of the theory of powers which approaches from a somewhat different angle (but also is skeptical about the modal nature ascribed to powers by Molnar as well as McKitrick), see the paper “What Do Powers Do When They Are Not Manifested?” by Stathis Psillos, available on his website. Thanks to Antonio for alerting me to this paper.

Powers and Property Dualism

Powers (or dispositional properties) are the centerpiece of George Molnar’s causal realist metaphysical model. The following question arises: are powers the only sort of property, or are there others?

Molnar considers whether powers (with the features he ascribes to them) could be the star players in an ontological monism (called pan-dispositionalism). It would seem that adopting pan-dispositionalism, along with the natural assumption that manifestations of dispositions constitute changes in the properties of objects, leads to a regress. Powers only manifest as changes to other powers. But is this a vicious regress? Molnar considers a couple of arguments that it is indeed vicious. If objects are things which take up space, then powers need to be joined by space occupying properties in order to constitute objects. But a look at particle physics seems to show that elementary constituents of nature do not have volume or occupy space in the way common sense implies. So this doesn’t seem to be a convincing objection – it’s not clear that objects need “space-occupying” non-power properties. A second objection says that objects need to have non-power properties which are qualities. But are there mind-independent physical qualities? What are they? Candidates such as size, shape, color are all phenomenological, rather than fundamentally physical, according to Molnar.

Molnar doesn’t see that the regress objections are fatal, but nevertheless concludes pan-dispositionalism is unlikely to be true for a posteriori reasons. Since powers are intrinsic to objects (in his theory), he considers the reality that they are “portable”. They are not necessarily altered if I move the object somewhere else. He sees the need for non-powers which are responsible for what scientists call symmetry operations (hence “S-properties”). These are essentially positional properties (positions in space-time) with one exception – if parts of a complex object have identical powers, and they exchange roles (say swapping the two hydrogen atoms in a water molecule), the powers of the complex object are not affected. This is a property of numerical identity.

So, Molnar does end up with a property dualism. There are powers, which are intrinsic dispositions of objects; and there are non-powers, which are extrinsic and basically have to do with placement of objects in space-time.

Comments:
Certainly, as property dualisms go, this is a pretty bare bones version compared to what the term “dualism” usually connotes. On the other hand, while Molnar is presenting a pretty ambitious metaphysical system, he is not trying to explain the mind, which is what traditionally motivates dualistic theories.

One critique I have centers on Molnar’s reliance throughout on his interpretations of physics. Powers are deemed intrinsic because, for instance, charge seems like an irreducible property of an electron. He says qualitative properties like size and shape don’t exist, because they do not feature in physics. He argues positional properties make sense because of symmetry operations which can be conducted on physical systems. A mostly unstated but crucial assumption underlying all of this is a somewhat old-fashioned view that physics supports the conception of objects moving around in a static space-time container. So a theory of powers which is motivated largely by a priori analysis of causation has its details shaped by these a posteriori inputs from physics. There are a couple of obvious concerns: first that his interpretations of physical theories may be incorrect, and second, that the theories he’s interpreting are provisional and may be superseded.

We don’t have a final theory of physics yet, but we can make an educated guess that the conception of objects moving in a space-time container (already extremely distorted in quantum field theory) will not survive. In General Relativity, there is a dynamic interaction between space-time and matter fields, and this seems to compromise the separation of properties into powers and positional properties (doesn’t a dynamic space-time need powers, too?). Further, in some quantum gravity research programs (my favorite ones), both space-time and matter fields are seen as emerging from a more fundamental basis (specifically a causal network of quantum mechanical interactions).

Still, the idea that positional properties are needed seems right to me. The nature of quantum mechanical propensities appears to depend on the relation between quantum systems. In a theory featuring a causal network of quantum mechanical interactions, causation would depend both on propensities (powers) and position in the network. One thing I think we could drop altogether is the idea of an object. What we think of as objects would be complex patterns of causal events in this way of thinking.

Pan-Intentionality

George Molnar sets out 5 key features of power properties: directedness, independence (they exist whether manifested or not), actuality, intrinsicality, and objectivity (mind-independence). His discussion of directedness is very interesting, as he argues that the directedness of powers has all the elements associated with intentionality. Therefore, the existence of (mind-independent) causal power properties means that physical intentionality is a ubiquitous feature of the world. (Please note the title of this post is my creation, and not a term used by Molnar).

The paradigm accounts of intentionality are those of mental intentionality due to Brentano and like-minded philosophers. In fact, Brentano took intentionality to be what distinguishes the mental from the physical. In philosophy of mind, a debate of the following sort has taken place: a dualist would make the case for the uniqueness and irreducibility of mental intentionality; a materialist would (rarely) claim that introspectively revealed intentional mental states are illusory, or would (more commonly) argue that physical things also exhibit intentionality and either take an instrumentalist rather than realist view of the whole phenomenon, or suggest a way to reduce it to non-intentional physical description. The dualist might counter that the examples of physical intentionality (a map, for instance) are all examples of derived intentionality with true mental intentionality being the origin of these seeming cases. (There is obviously immensely more to these debates than this caricature: see this SEP article).

Molnar turns this all around. He accepts the existence of mental intentionality and argues that “something very much like intentionality is a pervasive and ineliminable feature of the physical world.” (Emphasis original, Ch.3, p.61).

He presents these parallels between the directedness of powers and the intentionality of mental states:
1. Physical powers, like mental states, are directed towards something beyond themselves. In the case of the power, it is directed toward its manifestation.
2. In both cases, they can exist even if their intentional object does not exist. A power can remain unmanifested.
3. There can be indeterminacy about the intentional object. The power can be a propensity toward a manifestation.
4. Finally, Molnar describes a parallel between two semantic criteria for the intentional as applied to the two cases: the non-truth functionality of the intentional reference and referential opacity.

Molnar considers several possible objections to the notion of physical intentionality.

He looks at objections which try to point out other distinctive aspects of mental intentionality which counter the analogy. It seems there can be impossible intentional objects and absolutely unique intentional objects in the mental realm but not in the physical. He thinks there are merits to these cases of potential disanalogies, but in the first case, representations of impossible objects are a minor and atypical example of mental states, and in the second the uniqueness seems to depend on the experiential rather than the intentional nature of the state. These cases don’t make intentionality the demarcation between mental and the physical. So the analogy seems robust enough.

The most important possible objection has to do with the relationship between intentionality and meaning. Mental states are directed toward their intentional objects by representation, where the representation (whether pictorial, symbolic or in some other form) provides meaning. The states are “about” the objects. It seems we can’t extend this to the physical: power properties do not represent. Solubility is directed toward the dissolving of the solid, but doesn’t feature a representation of the event: it isn’t “about” it, in that way. Molnar’s strategy, here again, is not to deny the presence of semantic properties of mental states, but to loosen the tie between representation/aboutness and intentionality by pointing out paradigm cases of mental intentionality which do not include aboutness.

He points out that even in the case of perception, the perception cannot be wholly reduced to a representation. But he concedes it still has a great deal to do with representation. A much better example to use for a mental state without representation is in the realm of bodily sensation, and specifically pain. Pains are mental states which meet the four criteria for intentionality discussed above. But do pains have meaning above and beyond these intentional features? Are there representational features? Molnar says no: “…a headache does not represent my head hurting, it is my head hurting.” (Emphasis original, p. 77) The only sense it makes to say that the pain represents the bodily hurt involved is in a sense where you might say an effect represents its cause. And of course one could say this in cases of physical causation as well. If this is meaning, it is a form of natural, non-representational meaning. Molnar expands on the example to assert there are two kinds of mental intentionality, roughly corresponding to a traditional distinction between the rational and the sentient. The first can be analyzed in terms of representational content of the state, the second cannot. The second kind is the kind which is also true of the power properties of the physical world.

A last objection, of interest to me of course, is referred to by Molnar as “the threat of panpsychism” (p.70; why it is so darn “threatening”?). The argument is that the case for physical intentionality actually makes the case that the mental realm is co-extensive with what we think of as the physical realm. Molnar says he would not endorse this argument, because while he is ruling out using intentionality to demarcate the mental from the physical, there should be other ways of doing so, such as the “capacity for consciousness”. But, alas, this goes beyond the aims of the book. It is my view that the most elegant and compelling metaphysical account sees the human mind as a (particularly interesting) complex instance of a natural causal nexus which is ontologically grounded in the same way as the rest of the universe. No ontological demarcation is needed or wanted.

George Molnar and the Powers That Be

George Molnar’s Powers: A Study in Metaphysics appeared in 2003, with a paperback version following recently. The book presents a realist theory of causal metaphysics founded on a detailed ontological treatment of dispositional properties, or powers. Molnar’s work was brought to my attention last fall by an e-mail correspondent, to whom I’m grateful. I plan to present some notes and thoughts about the book over a couple of posts.

The book is a posthumous publication, Molnar having died in 1999. Some brief biographical information is provided in the introduction by Stephen Mumford (see also this webpage [UPDATE: 8 March 2011 - this was a link to a page about Molnar - now gone), as well as in a preface by D. M. Armstrong. Born in Budapest, Molnar and his family escaped the Nazis and he settled in Australia. He became a philosopher and published a handful of metaphysical papers early in his career. Then leftist political activities led him to depart his university post and exit formal academic philosophy for a couple of decades until just a few years before his death. In those years, this book took shape.

According to Mumford, who prepared the manuscript for publication, the chapters which present the main theory were largely complete; the manuscript lacked an introductory chapter and only fragments existed of the intended final chapters on application of the theory of powers to various metaphysical problems. Mumford has provided a helpful introduction, and edited the final fragments into a condensed last chapter.

Molnar’s theory is a realist account of dispositional properties as causal powers. This realism about dispositional properties and causality is in contrast to work in the Humean tradition which would eliminate dispositional properties and reduce apparent causal power to mere correlation. A traditional strategy is to employ a conditional analysis. Rather than ascribe the dispositional property of solubility to X, one simply notes that if X is placed in water, then it will dissolve. Another way to approach eliminating powers is to claim they can be reduced to categorical micro-physical properties (although many would view charge, mass, spin et. al as paradigm dispositional properties). Molnar will defend dispositional properties as real and ineliminable causal powers of objects.

Molnar’s Ontological Categories

A. Tropes. Molnar wants to present a full ontology of powers, so he must answer the question: what kind of properties are they? His answer is that properties are tropes. He thinks that nominalists are right to distrust the idea that properties as universals are real but err in rejecting all realism about properties. Realists are right in their realism, but wrong about universals, which are too inconsistent with naturalism. There are sections discussing the characteristics of tropes in great detail in Ch. 1, which I will pass over for now. I should note that in addition to powers, Molnar will find a need for non-power properties as well, leading to a property dualism.

B. Objects. There is a classic problem with tropes, however, which is explaining how they bunch up in coherent ways. Attempts to posit ways to bundle tropes together without adding something new to the mix are unsuccessful (see my old post with a link to work on this topic by Dr. Bill Vallicella). Molnar bites the bullet and admits objects as an additional ontological category. Powers are powers of objects. (Later in the book, though, he will admit ungrounded powers as well).

C. Relations. In Molnar’s assessment, objects are separable from their location in space-time. This leads him to add relations as an additional irreducible ontological category.

Given these ingredients, at least one ontological category Molnar will not need are “states of affairs” (or facts or situations, etc.), which he criticizes in section 2.3.

Still, I think that one can be more economical yet with regard to the size of the ontological zoo. I’ll say more later after a discussion of powers, but I think an event ontology can improve on an object oriented ontology.