Over the last several decades conversations about dispositions (or powers) have been commonplace among philosophers.[1] According to dispositionalists, properties like fragility are said to have triggers (or stimulus conditions)—like dropping a glass onto the floor—that bring about their manifestations, e.g., breaking, cracking, shattering, etc. What’s more, triggers and manifestations are often claimed to play some sort of individuating role with respect to powers. These considerations raise a philosophical question. Are powers—fragility, flammability, solubility, and the like—ontologically simple or complex? If they are complex, can we understand them compositionally? For example, is breaking a part of the power of fragility? Or is talk of parthood merely an instance of speaking with the vulgar? This thought-provoking collection of twelve essays edited by Christopher J. Austin, Anna Marmodoro, and Andrea Roselli, addresses the ontological complexity of dispositions. The editors partition the essays into three sections: Part 1, “Parts of Powers” discusses part-whole relations “within a power”; Part 2, “Composition of Powers”, discusses mereological relations “among powers”; Part 3, “Power Mereology in Science” is devoted to issues in the philosophy of science. For this review I will try to summarize some main takeaways from each essay and offer critical and constructive remarks where appropriate.
In their introduction, the editors motivate the discussion with the claim that the literature on powers and dispositions often assumes that powers are simple, fundamental entities. Further, they claim that multi-track accounts—accounts which say that powers are individuated by more than one type of stimulus/manifestation—only “organize the complex manifestation of certain powers into ‘tracks’ but do not explain how this complex manifestation derives from the power” (1). Austin expands on this criticism later in Ch. 3. Multi-tracking accounts only tell us about the “counterfactuals assigned to a single power” (63). This can tell us about the “truthmaking relations that power is involved in”, but “these relations are incapable of providing meaningful information about the nature of powers” (63). Thus, these accounts treat powers as “little more than ‘black boxes’ whose extrinsic complexity stems from a we-know-not-what intrinsic metaphysical foundation” (64).
The first two contributions, Aaron Cotnoir’s chapter, “Carving up the Network of Powers” (Ch. 1), and the second essay from Robert Koons, “Parts and Grounds of Powers” (Ch. 2), are by far the most formal and systematic of the essays.
Cotnoir develops a graph-theoretic network of powers that can—following Plato’s metaphor—be carved according to natural joints, and he considers three methods for carving this network: subcollection, clustering, and coordination. Meanwhile, Koons develops an approach on behalf of the “extreme nominalist” (42), which builds powers out of equivalence classes of conditional facts, and invokes a sui generis conditional that expresses “the fact that if a certain n-tuple of thing were in a certain condition A, some joint power of those things would manifest itself in outcome B” (42). Both Cotnoir’s and Koons’ systems offer ways to assess the “naturalness” of the resulting complexes: Cotnoir suggests that “unnaturalness” can be measured by the degree of crosscutting between clusters, while Koons suggests a criterion for determining when entities are of the same natural kind.
In Ch. 3, “Complex Powers: Making Many One”, Christopher Austin identifies two ways in which powers can be regarded as complex: “polygeny”—the idea that for a power there can be “many distinct inputs which causally contribute toward the coming about of its manifestation” (61)—and “pleiotrophy”, “which occurs when a single power has many distinct manifestations which may produce from the obtaining of one or more distinct stimuli” (62). An account of the complexity of powers, Austin argues, must accommodate these varieties of complexity in telling a metaphysical story about when many powers become one. After critiquing the metaphysical inadequacy of multi-tracking accounts, he goes on to consider two strategies, essentialist and emergentist accounts, but concludes ultimately that neither of these approaches is satisfactory. However, the main lesson seems to be that an account of the unity of complex powers needs to fall somewhere between accepting mereological fusions and emergence.
In Ch. 4, “Powers as Mereological Lawmakers”, Michael Traynor takes a bottom-up approach about mereological laws. Traynor begins with two Inclusion Principles, along with remarks by George Molnar (2003), to generate an argument that powers can be parts of objects. He goes on to argue that “powers give rise to mereological laws” and considers implications for this claim with respect to debates about whether mereological laws (paralleling similar arguments about laws of nature) are metaphysically necessary or contingent.
Nicky Kroll’s essay, “Determinable Dispositions” (Ch. 5) forgoes a mereological approach altogether and instead assesses the complexity of dispositions in terms of the determinate/determinable relation. Kroll cites Quine’s (1956) observation that desires can be non-specific and goes on to argue that dispositions can be non-specific as well. He goes on to draw three lessons: (i) that determinable dispositions are distinct from multi-track dispositions; (ii) many alleged multi-track dispositions—fragility, irascibility, knowing French—are in fact determinable dispositions; (iii) standard arguments for the claim that a disposition is multi-track turn out to be invalid.
In Ch. 6, Sophie Allen distinguishes between cases of direct composition—the part and the whole are instantiated by the same individual—and cases of indirect composition—cases where an individual is a proper part of another. Allen gives several quite helpful examples, e.g., “The power to spring is part of the power to jump 7.5m.” (113), to make a compelling case that direct composition of powers takes place. However, she gives relatively short shrift to her criticisms of indirect composition. For example, one might appeal to Kathrin Koslicki (2008), whose hylomorphic mereology posits structural proper parts, as a way of \ responding to Allen’s worry about indirect composition violating extensionality.
In Ch. 7, Vera Hoffmann-Kolss explores the non-mereological issue of the logical complexity (i.e., disjunctive) of variables for interventionist models of causation. She argues that interventionist models should make use of disjunctive variables, like “1 if Person P consumes apples or apple products or does not take a pain killer; 0 otherwise”, but that these conflict with proposed definitions “intervention”. However, she claims that these problems can be addressed if interventionists take the values of variables to be properties that “confer conditional causal powers on their bearers” à la Sydney Shoemaker (1980).
In Ch. 8 Xi-Yang Guo and Matthew Tugby sketch and defend an account of collective instantiation analogous to plural instantiation. Key to their argument is the idea of distributive occurrences of predication and instantiation: G occurs distributively where “the Fs are G is equivalent to each F is G” (148). For example, “The students in my class are engaged” might distribute to “Each student in my class is engaged”. By contrast, a predicate like “make a star pattern” in “The lights make a star pattern” does not distribute, since the claim is not equivalent to “Each light makes a star pattern”. Thus, according to Guo and Tugby, “make a star pattern” is a non-distributive, collective predicate. However, I’m not so sure that denying distribution entails collectivity. Take examples of generics or bare plurals. “Mosquitos carry yellow fever” does not distribute to “Each mosquito carries yellow fever”. But it also seems incorrect to say that “carries yellow fever” is collectively predicated of the class of all mosquitos since only a couple of species are associated with carrying the disease. Collective predication/instantiation seems to require more than just being non-distributive.
Joaquim Giannotti’s Ch. 9 considers a special composition question about powers (an analogue to the special composition question for material objects), and argues that a modified version of Marmodoro’s (2017) answer is the best way to achieve a restricted (i.e., neither a nihilist nor a universalist) answer to when powers compose. Gianotti goes on to argue that this refined “Marmodoro Condition”, combined with other premises from quantum theory, yields the conclusion that there is an entity he calls the “powerful cosmos”, an object “composed of all the compossible fundamental powers instantiated across the universe” (168).
In Ch. 10 Michele Paolini Paoletti argues for the compatibility of a “naïve view of powers” and the idea that powers compose. According to Paoletti, the “naïve” view holds that there is a “strict, one-to-one correspondence between powers, their bearers, and their manifestations and activations, on the one hand, and the causes, effects, and causal processes on the other” (185). To close out the collection, the third and final section, Part 3, begins with Matteo Morganti’s (Ch. 11) essay, which explores a “Simple Theory” of property composition, where complex properties are “nothing over and above” their constituents, and argues that one can understand the properties of quantum entangled systems by invoking metaphysical coherentism. Simone Gozzano (Ch. 12) completes the collection by considering whether phenomenal states, like tasting white wine, can be considered complex dispositional properties composed of constituents like the experience of the taste of hay, or the taste of green apple. These are further decomposable into protophenomenal atoms, resulting in a picture that fits into current discussions about Russellian monism and panpsychism.
As one can see the essays display at times very different approaches to the question of the complexity of powers. As a result, the attempt to group certain essays into Parts 1, 2, and 3 is a little strained at times. For instance, Cotnoir’s piece on carving a network of powers seemed more appropriate for Part 2 about the relations between powers, while Allen’s might be a better fit for Part 1 on part-whole relations within a power. In a similar vein, it’s clear that not every essay in the collection is about the mereology of powers—notably Kroll approaches complex powers in terms of the determinable/determinate distinction, Hoffmann-Kolss is concerned with the logical complexity of variables for interventionism, Guo and Tugby sketch an account of collective instantiation, and Morganti explicitly says he’s not concerned with a mereological notion of composition and instead focuses on the factorizability of probabilities for entangled quantum systems. In this respect, the book’s subtitle, “Essays on the Mereology of Powers” is a bit of a misnomer; perhaps “Essays on the Metaphysical Complexity of Powers” would have been more appropriate. After all, understanding the ontological complexity of powers needn’t only be cashed out mereologically, and a research question like this may benefit from looking at the theoretical landscape in several divergent ways.
Overall, there’s much of interest to be gleaned from this book. It covers a wide range of approaches to the question of the metaphysical complexity of powers, both mereological and non-mereological alike. Despite some deviation from the editors’ stated goal of offering a mereological approach to the complexity of powers, I think the book can be framed as having a different and broader aim: to examine the ontological complexity of powers by offering a more metaphysically robust story, one that goes beyond merely saying that powers are individuated by their stimuli or manifestations. With this aim in mind, I think the book shows that there’s quite a bit of potentially fruitful philosophical ground here left to explore.
REFERENCES
Koslicki, K. (2008). The Structure of Objects. Oxford: Oxford University Press.
Marmodoro, A. (2017). “Power Mereology: Structural Powers Versus Substantial Powers” in
Philosophical and Scientific Perspectives on Downward Causation, Eds. M. Paolini Paoletti, F. Orilia, 110–129. New York: Routledge.
Molnar, G. (2003). Powers: A Study in Metaphysics. Oxford: Oxford University Press.
Quine, W.V. (1956). “Quantifiers and Propositional Attitudes”. Journal of Philosophy, 53 (5), 177–187.
Shoemaker, S. (1980). “Causality and Properties” in Time and Cause: Essays Presented to
Richard Taylor, Ed. P. Van Inwagen, Reidel: 109–136.
[1] I will follow the convention set by the editors and several contributors by using “power” and “disposition” interchangeably.