Friend, T. and Kimpton-Nye, S. ‘Dispositions and Powers’. Cambridge University Press.

As we understand them, dispositions are relatively uncontroversial ‘predicatory’ properties had by objects disposed in certain ways. By contrast, powers are hypothetical ‘ontic’ properties posited in order to explain dispositional behaviour. Chapter 1 outlines this distinction in more detail. Chapter 2 offers a summary of the issues surrounding analysis of dispositions and various strategies in contemporary literature to address them, including one of our own. Chapter 3 describes some of the important questions facing the metaphysics of powers including why they’re worth positing, and how they might metaphysically explain laws of nature and modality.

Peer Reviewed Journal Publications

Forthcoming. ‘The Possibility Bias is not Justified’. Journal of the American Philosophical Association.

Necessity, but not possibility, is typically thought to be rare and suspicion-worthy. This manifests in an asymmetry in the burden of proof incurred by modal claims. In general, claims to the effect that some proposition is impossible/necessary require significant argumentative support and, in general, claims to the effect that some proposition is possible/contingent are thought to be justified freely or by default. Call this the possibility bias. In this paper, I argue that the possibility bias is not epistemically justified. We should regard possibility with at least as much suspicion, that is to say as incurring at least as much of an explanatory demand, as necessity. In fact, I suggest that we might even be justified in reversing the burden of proof asymmetry and adopting a necessity bias. This has quite radical implications for philosophical methodology and hence for many first-order philosophical concerns.

Forthcoming. ‘On Some Objections to Powers-BSAs’. The Philosophical Quarterly.

This paper responds to Friend’s (2023) critique of the Powers-BSA, a view according to which laws of nature are efficient descriptions of how modally laden properties (powers) are possibly distributed in spacetime. In the course of this response, the paper discusses the nature of scientific and metaphysical explanation, the aim of science and the structure of modal space.

Forthcoming. ‘Debating Powers: Where the Real Puzzle Lies’. Inquiry.

Stephen Mumford and Alexander Bird disagree about which properties are powers and, correspondingly, about the extent of the philosophical work to which powers may be put. Unfortunately, there is an important respect in which these authors are talking past each other and so the reason for their disagreement remains obscured. I highlight what has gone wrong in their recent exchange, attempt to clear up the confusion and pinpoint the true source of their disagreement. My hope is to redirect the efforts of these authors and their followers onto more pressing foundational issues in the metaphysics of powers.

Kimpton-Nye, S. (2023). ‘How to be a powers theorist about functional laws, conservation laws and symmetries’. Philosophical Studies.

This paper defends an account of the laws of nature in terms of powers from the threat posed by functional laws, conservation laws and symmetries. It thus shows how powers theorists can avoid ad hoc explanations and resist an inflated ontology of powers and governing laws. The key is to understand laws not as flowing from the essences of powers, as per Bird (2007), but as features of a description of how powers are possibly distributed, as per Demarest (2017), Kimpton-Nye (2017; 2021a) and Williams (2019); call this the Powers-BSA. This underappreciated powers-based account of laws is continuous with actual scientific practice and thereby quite naturally accommodates functional laws, conservation laws and symmetries. This paper thus positions the Powers-BSA as the leading anti-Humean account of the relationship between laws and properties.

Kimpton-Nye, S. (2022). ‘Pandispositionalism and the Metaphysics of Powers’. Synthese.

Some philosophers maintain that physical properties are irreducibly modal: that properties are powers. Powers are then employed to provide explanations of other phenomena of philosophical interest such as laws of nature and modality. There is, however, a dispute among powers theorists about how far the powers ontology extends: are all manner of properties at all levels of fundamentality powers or are powers only to be found among the fundamental properties? This paper argues that the answer to this question depends on the details of the metaphysics of powers. More specifically, this paper argues that if one understands powers as qualitative grounds of dispositions (call this qualitative dispositional essentialism), as opposed to properties whose essences are constituted by dispositions (as orthodox dispositional essentialists would have it), then all properties, be they fundamental or macro, are powers, i.e., pandispositionalism is true. The Conclusion: If qualitative dispositional essentialism is true, then pandispositionalism is true, is significant because there is increasing concern that orthodox dispositional essentialism is explanatorily deficient and perhaps even incoherent, meaning that qualitative dispositional essentialism is gaining increasing support in the literature on powers. All things considered, then, it is beginning to look more likely that pandispositionalism is true simpliciter.

Kimpton-Nye, S. (2022). ‘Laws of Nature: Necessary and Contingent’. The Philosophical Quarterly.

This paper shows how a niche account of the metaphysics of laws of nature and physical properties—the Powers-BSA (Demarest 2017; Kimpton-Nye 2017; Williams 2019)—can underpin both a sense in which the laws are metaphysically necessary and a sense in which it is true that the laws could have been different. The ability to reconcile entrenched disagreement should count in favour of a philosophical theory, so this paper constitutes a novel argument for the Powers-BSA by showing how it can reconcile disagreement about the laws’ modal status. This paper also constitutes a defence of modal necessitarianism, the interesting and controversial view according to which all worlds are nomologically identical (Edgington 2004; Schaffer 2005; Wilson 2013; Kimpton-Nye 2020), because it shows how the modal necessitarian can appease the orthodox contingentist about laws.

Kimpton-Nye, S. (2021). ‘Reconsidering the Dispositional Essentialist Canon’. Philosophical Studies.

Abstract: Dispositional Essentialism is a unified anti-Humean account of the metaphysics of low-level physical properties and laws of nature. In this paper, I articulate the view that I label Canonical Dispositional Essentialism (CDE), which comprises a structuralist metaphysics of properties and an account of laws as relations in the property structure. I then present an alternative anti-Humean account of properties and laws (still somewhat in the dispositional essentialist spirit). This account rejects CDE’s structuralist metaphysics of properties in favour of a view of properties as qualitative grounds of dispositions and it rejects CDE’s view of laws as relations in favour of a view of laws as features of an efficient description of possible property distributions. I then defend this view over CDE on the grounds that it can overcome an explanatory shortcoming of CDE and that it achieves a level of continuity with science that CDE fails to achieve. The upshot of this paper is a significant narrowing of the range of possibilities in which the absolutely best unified account of laws and properties resides.

Kimpton-Nye, S. (2021). ‘Can Hardcore Actualism Validate S5?’ Philosophy and Phenomenological Research.

Abstract: Hardcore actualism (HA) grounds all modal truths in the concrete constituents of the actual world (see, e.g., Borghini and Williams 2008; Jacobs 2010; Vetter 2015). I bolster HA, and elucidate the very nature of possibility (and necessity) according to HA, by considering if it can validate S5 modal logic. Interestingly, different considerations pull in different directions on this issue. To resolve the tension, we are forced to think hard about the nature of the hardcore actualist’s modal reality and how radically this departs from possible worlds orthodoxy. Once we achieve this departure, the prospects of a hardcore actualist validation of S5 look considerably brighter. This paper thus strengthens hardcore actualism by arguing that it can indeed validate S5–arguably the most popular logic of metaphysical modality–and, in the process, it elucidates the very nature of modality according to this revisionary, but very attractive, modal metaphysics.

Kimpton-Nye, S. (2020). ‘Necessary Laws and the Problem of Counterlegals.’ Philosophy of Science.

Abstract: Substantive counterlegal discourse poses a problem for those according to whom the laws of nature are metaphysically necessary. In this paper, I discern two types of necessitarianism about laws: Dispositional Essentialism and Modal Necessitarianism. I argue that Handfield (2004)’s response to the problem of counterlegals cannot help the Modal Necessitarian who maintains the strong view that all possible worlds are identical with respect to the laws of nature. After noting the use of counterlegal reasoning in scientific modeling, and taking inspiration from Frigg (2010)’s account of scientific models as fictions, I suggest a fictionalist treatment of counterlegals. My response to the problem of counterlegals on behalf of the Modal Necessitarian thus constitutes a rejection of the premise that we must provide a realistic semantics for counterlegals. Fictionalism is not limited by the range of metaphysical possibilities and thus affords the Modal Necessitarian the means to account for the apparent substance of counterlegals even granting the metaphysical necessity of the laws.

Kimpton-Nye, S. (2018). ‘Hardcore Actualism and Possible Non-Existence.’ Thought: A Journal of Philosophy.

Abstract: According to hardcore actualism (HA), all modal truths are grounded in the concrete constituents of the actual world. In this paper, I discuss some problems faced by HA when it comes to accounting for certain alleged possibilities of non‐existence. I focus particular attention on Leech (2017)’s dilemma for HA, according to which HA must either sacrifice extensional correctness or admit mere possibilia. I propose a solution to Leech’s dilemma, which relies on a distinction between weak and strong possibility. It remains the case, however, that HA cannot capture certain iterated de re possibilities of non‐existence and that it is committed to a stock of necessary existents. But I still think that the virtues of the view outweigh these costs.


Abstract: I argue that an unHumean ontology of irreducibly dispositional properties might be fruitfully combined with what has typically been thought of as a Humean account of laws, namely, the best-system account, made popular by David Lewis (e.g., 1983, 1986, 1994). In this paper I provide the details of what I argue is the most defensible account of Humean laws in an unHumean world. This package of views has the benefits of upholding scientific realism while doing without any suspect metaphysical entities to account for natural law. I conclude by arguing that the Humean laws-unHumean ontology package is well placed to provide an account of objective, nontrivial chances, a famous stumbling block for the Humean laws-Humean ontology package developed by Lewis.

Invited Contributions to Edited Volumes

‘Laws (Scientific).’ Forthcoming in The SAGE Encyclopedia of Theory in Science, Technology, Engineering, and Mathematics, edited by James Mattingly.


Introduction: Laws of nature are central to science, but what is a law of nature? It is quite easy to give some examples: Coulomb’s Law of electrostatic attraction, Snell’s law of refraction, the Schrödinger equation for the evolution of a quantum-mechanical system. But what do these things have in common in virtue of which they get to count as laws of nature? What is it to be a law of nature? For short, and from now on: what is a law of nature? While this is primarily a philosophical question, it should be no less interesting to scientists and students of science than, say, the foundations of quantum mechanics. Of course, there are many scientists to whom the latter is of no interest: the “shut up and calculate” types. But if one is not content with merely using science as a tool and would like to go further and investigate what science says the world is really like, then one should find something of interest in our philosophical question: “what is a law of nature?”.

Book Reviews

The Nature of Contingency: Quantum Physics as Modal Realism. By Alastair Wilson. (Oxford: OUP, 2020. Pp. 219. Price £50.00.)


A Case for Necessitarianism by Amy Karofsky (Routledge, 2021). ISBN 9781032026169

Thesis Summary

Common Ground for Laws and Modality (click here for full text)

In my PhD thesis, I argue that scientific inquiry into the laws of nature can, to a large extent, inform philosophical inquiry. I build up to this conclusion by accounting for the laws of nature and metaphysical modality in terms of low-level physical properties (just properties from now on), such as charge, mass and spin.

First, I argue that properties are necessarily connected with the range of behaviours towards which they dispose their bearers. Furthermore, I describe exactly how these necessary connections comes about – a task that has been largely neglected in the literature. To get a sense of the argument, consider a spherical object – call it ball. Ball is disposed towards various behaviours: rolling, casing an elliptical shadow, fitting through round holes, etc. Why is ball disposed to behave in these ways? Answer: because it is spherical – the very nature of the property sphericity explains these behaviours in a similar way to that in which the squareness of a peg explains its inability to fit in a round hole. Moreover, anything spherical would be similarly disposed to, e.g., roll. I argue that the property sphericity explains rolling in such a way that the property and the behaviour are necessarily connected. Furthermore, I argue that the relationship between all properties, including those such as charge and mass, and the behaviours with which they are associated can be understood in this way. It follows, contrary to what has been claimed by many philosophers (e.g., Armstrong 1999; Lewis 2009), that it is in no sense possible for an individual to instantiate the property positive charge (for example) and not be disposed to accelerate towards instances of negative charge.

Properties, on the conception sketched above, determine how their instances can be arranged throughout space and time. The laws of nature, I argue, are features of a particularly efficient description of how all and only the properties found at our world are possibly arranged. This view of laws has the benefits of being consonant with actual scientific practice of formulating widely applicable generalizations. It also has the potential to provide a unified account of the laws of nature and chance – something that has proved notoriously challenging (see, e.g., Bigelow, Collins, and Pargetter 1993; Lewis 1994).

I argue that metaphysical modality is also a matter of how properties are possibly arranged throughout space and time. The intuitive thought behind this idea is that something is possible, the vase breaking, say, if (and only if) some property instances can be arranged, such that the vase is broken. Property instances, on this view, are a bit like building blocks and possibility is a matter of how those blocks can be arranged. How the “blocks” can be arranged is determined by the natures of the properties themselves, in much the same way in which ball’s tendency to roll is determined by its sphericity.

It follows from the above that facts about laws of nature and facts about metaphysical modality both hold in virtue low-level physical properties. Indeed, both concern possible arrangements of those properties. Since the laws of nature describe this information about possible property arrangements in a way that is efficient and accessible to us, scientific inquiry into the laws of nature should be our primary means of inquiry into what is metaphysically possible. The result is quite striking when we notice the ubiquity of appeals to metaphysical possibilities in all manner of philosophical arguments: scientific inquiry into the laws can yield a diversity of philosophical insights.