Publications

Published

• Hylomorphism
  Cambridge University Press, 2023

Aristotle’s doctrine of hylomorphism provides an account of composite entities in terms of  both matter and ’form’. I argue that there are modern versions of hylomorphism which affirm a real and fundamental distinction between living organisms and heaps of matter, and which can provide a credible alternative to dualism and physicalism in characterising the interface between physics and biology. #Hylomorphism

• Surprises in Theoretical Casimir Physics: Quantum Forces in Inhomogeneous Media
  Springer, 2014

Many of the sticky forces we encounter in the macroscopic world, as well as attractive forces that keep chemical compounds together, contain a component which must be modelled using quantum mechanics to obtain accurate predictions.  I uncover new puzzles and paradoxes concerning these mysterious 'Casimir forces', demonstrating that our most sophisticated theories fail when confronted with dielectrics in which the refractive index of the medium is not uniform but gradually changes.  #Quantum-Forces

In Progress

• The Limits of Quantum Physics and the Emergence of Complexity
  with George Ellis, under contract with Cambridge University Press

Description pending .#Quantum-Forces, #Hylomorphism

Published

• Neo-Aristotelian Metaphysics and the Theology of Nature,
  co-edited with R.C. Koons and J. Orr, Routledge, 2021


There is growing interest in Aristotelian approaches to the philosophy of science, yet few metaphysicians have engaged directly with the question of how a neo-Aristotelian philosophy of nature might change the landscape for theological discussion concerning theology and naturalism, the place of human beings within nature, or the problem of divine causality. I initiated this edited collection to help advance a metaphysically unified framework that accommodates scientific and theological knowledge. #Hylomorphism

• Neo-Aristotelian Perspectives on Contemporary Science,
  co-edited with R.C. Koons and N.Teh, Routledge, 2017


There has been a rapid development in the philosophy of the specialised sciences and a resurgence in Aristotelian metaphysics. Despite these recent trends, few 'neo-Aristotelian' metaphysicians have engaged directly with the philosophy of the specialised sciences, or provided a critical and systematic treatment of Aristotelian concepts such as "hylomorphism" or "substance", in the light of our best physics. I initiated this edited collection to advance this discussion. #Hylomorphism #Quantum-Powers

• Forces of the Quantum Vacuum: an introduction to Casimir Physics,
  co-edited with U. Leonhardt, World Scientific, 2015


It is often supposed that the quantum-fluctuation (Casimir) forces arising between macroscopic bodies or between molecules are nothing but a sum of microscopic Van Der Waals forces between particles; a sum which is too large to compute in practice.  This reductionist claim, however, glosses over some significant details.  This textbook I designed (with the input of expert physicists) starts with basic ideas in quantum mechanics and builds its way to a sophisticated form of macroscopic QED, where it is clear that our best description of these quantum forces is one in which classical, macroscopic features of the system are implicated.   #Quantum-Forces

In Progress

• A History of Natural Law: From the Ancient World to the New Aristotelianism
  co-edited with J. Dyer, under contract with Cambridge University Press

Description pending.

Published

• Prime Matter and Modern Physics
  Ancient Philosophy Today, Volume 6, Number 1, April 2024

The notion of ‘prime matter’  is often dismissed as a piece of scholastic sophistry; part and parcel of a medieval philosophy of nature which crashed and burned in the wake of the Scientific Revolution. The concept of prime matter as a metaphysical constituent of material things, however, had at least two well-defined roles to play in the metaphysical systems of scholastic philosophers: it was invoked (i) as that which underlies substantial change and (ii) as that which individuates substances. It may also have a role in modern physics... #Hylomorphism

In Progress

• Why Middle-Sized Matters to Scientific Inquiry
  co-edited with Timothy O’Connor, Topoi

In contemporary philosophy, there has been a tendency to attribute fundamental reality to the microscopic or cosmic scales explored by our best physics, whilst the ‘middle-sized’ things that exist between the microscopic and the cosmic scale have been assigned (at best) a secondary ontological status. However, the majority of scientists are not concerned with the microscopic or cosmic scale, but with the properties of middle-sized phenomena and the behaviour of middle-sized things. And scientists are only able to uncover facts about the microscopic or cosmic scale by using middle-sized instruments which they can perceive and manipulate. The papers in this special issue explore the nature and reality of middle-sized things. #Hylomorphism

• Why Middle-Sized Matters to Science and Religion
  co-edited with Christopher Oldfield, Scientia Et Fides

 The field of science and religion has largely developed in consideration of scientific images of the world focused at the microscopic or the cosmic scale. From the extreme perspective of Carl Sagan’s “distant vantage point”, the middle-sized scale which concerns the majority of working scientific and religious practitioners seem out of place, left out of the picture.  This special issue aims to broaden its focus by asking why Middle-Sized Things matter for both science and religion, and how we should think about their nature, reality and significance. #Hylomorphism

Published

• “Cosmopsychism and the Laws of Physics: A Hylomorphic Perspective”
  Journal of Consciousness Studies, 31(9-10), 2024

I outline a hylomorphic account of physical reality in which the cosmos has mental properties which explain its nomological order. According to this theory, the cosmos is directed in its temporal development toward certain ends or goals which it intends, and these ends are immanent to the cosmos rather than being imposed upon it. My object in doing so is to argue that, contrary to Sean Carroll (2021), a view of physical reality as having intrinsically mental aspects need not induce any modifications of the known laws of physics. I propose a trilemma for Carroll in which he should either: abandon naturalism, by admitting that the laws of physics are imposed by a divine mind; abandon realism, by conceding that 'laws' are constructed by human minds; or embrace cosmopsychism, by attributing mind to the cosmos.

• “Whose Hylomorphism? Which Theory of Prime Matter?”
  with M. Mosko, Ancient Philosophy Today: Dialogoi, 6(1), 2024

We consider a recent hylomorphic interpretation of non-relativistic quantum mechanics, which does not explicitly invoke any notion of prime matter in its original formulation. We argue that prime matter does in fact play a role in constituting and individuating particles in this theory, but that the notion of prime matter is distinct from Aquinas’s conception of prime matter.

• “Small Worlds with Cosmic Powers”
  The Journal of Philosophy, 120(8), 2023

What exists in a world described by the Bohmian theory of quantum mechanics? According to Mauricio Suárez, it contains particles which have multi-track powers. I argue that my own model, Cosmic Hylomorphism, which attributes causal powers to a Cosmic Substance composed of both matter and form, has an explanatory advantage: it captures our intuitions about laws in ‘Small Worlds’ which have only a few particles. #Quantum-Powers

• “The Myth of the Physical Given”
  Revue philosophique de Louvain, 119(1), 151-164, 2022

The Myth of the Physical Given is a tendentious story about the success of the sciences which seeks to normalise a certain interpretive structure that has been imposed upon the scientific image; one in which the whole truth about nature supervenes upon a physical reality that exists outside of the space of ends and goals.  I argue that it’s a mythology we have reasonable grounds to reject in the light of the Quantum Revolution in physics and the turn to powers in contemporary metaphysics.  #Quantum-Powers

• “What’s the matter with Super-Humeanism?”
  British Journal for the Philosophy of Science, 72, 2, 2021, 893-911

Does the physical world explored by the natural sciences consist merely of 'matter points', which are are nothing over and above the distance relations in which they stand? Michael Esfeld thinks so. I argue that Esfeld’s sparse ontology has counterintuitive consequences, however, and generates two self-undermining dilemmas concerning the nature of time and space. Contrary to Esfeld, I deny that super-Humeanism supports an ontology of microscopic particles that follow continuous trajectories through space.

• “Cosmic hylomorphism: a powerist ontology of quantum mechanics”
  European Journal for the Philosophy of Science, 11, 28, 2021

The 'Bohmian' interpretation of quantum mechanics is often presented as being, more or less, a return to a 'classical' conception of the physical world in which reality consists of discrete particles that follow continuous trajectories through space according to a law of nature. I argue that the highly non-local nature of this law stands in need of an explanation, however, and put forward an account of Bohmian mechanics in which the world is a hylomorphic substance composed of both matter and form.

• “Ontological aspects of the Casimir Effect"
  Studies in History and Philosophy of Modern Physics, Vol. 48, Part A, 2014, 84-88

The quantum forces between macroscopic bodies known as Casimir forces have been described, on the one hand, as being nothing but variations in the "zero point energies" of an all-pervading electromagnetic field, or, on the other hand, as being nothing but Van der Waals forces arising between the particles comprising material bodies. I argue that, in a general and consistently quantum-mechanical theory of light in media, Casimir forces arise out of the ground-state properties of a polariton field – a coupled, quantised system of dielectric material and electromagnetic fields  –  and are therefore reducible to neither.   #Quantum-Forces

• “Divergence of the Casimir stress in inhomogeneous media”

  with S. Horsley & U.Leonhardt, Physics Review A, 059901, 2013

The 'Lifshitz theory' of van der Waals forces proposed by Lifshitz in 1954 is a leading theory in condensed matter physics and physical chemistry for treating van der Waals forces between macroscopic bodies, where the bodies are treated as continuous media. We demonstrate that this theory runs into difficulties when the interacting bodies and/or the media in which they are immersed are treated as inhomogeneous (in this case, when the dielectric medium gradually varies in one direction): the stress tensor is not finite anywhere within the medium, whatever the temporal dispersion or index profile.   #Quantum-Forces

• “The Cutoff-dependence of the Casimir force within an inhomogeneous medium”

  with S.Horsley, Physics Review A 88, 013833, 2013

It is now known that there is a divergence in the stress tensor which is used to calculate the Casimir force in Lifshitz theory, for the case of inhomogeneous media. In this paper (and its erratum) we confirm that this divergence problem is peculiar to Lifshitz theory.  #Quantum-Forces

• “The Casimir force in a compressive transformation medium”
  Physics Review A, 063852, 2013

I have previously shown -- in collaboration with others -- that there is a divergence in the stress tensor which is used to calculate the Casimir force in Lifshitz theory: the stress tensor typically yields an infinite Casimir force, even in a case where the force must be zero. However, there are some special cases of inhomogeneous media in which this divergence does not arise. I consider the case of an idealized inhomogeneous metamaterial which, when introduced into a Casimir cavity, reduces the magnitude of the Casimir force: it does not contribute any additional scattering events, but simply modifies the effective length of the cavity, and consequently the predicted force in this case is finite and can be stated exactly.  #Quantum-Forces

• “Exact solution for the Casimir stress in a spherically symmetric medium”

  with U. Leonhardt, Physics Review D, 081701(R), 2011

Casimir suggested an intriguing model that could explain the stability of charged particles and the value of the fine-structure constant in terms of an attractive Casimir force which balances electrostatic repulsion. This model was reputedly shattered when it was subsequently shown that the vacuum force upon a spherical shell is repulsive and so could not possibly balance the electrostatic repulsion. However, we offer an exact, analytic calculation of the stress in a spherically symmetric medium surrounded by a perfect mirror, discovering an attractive stress which diverges at the mirror.  #Quantum-Forces

In Progress

• The Entanglement Problem for Psychological Hylomorphism
  with Robert C. Koons, invited by Res Philosophica

Description Pending.  #Quantum-Forces

• Powerist and Nomological Interpretations of Quantum Theory
  invited by Compass

Description Pending.  #Quantum-Forces

• Why Middle-Sized Matters: Quantum Realism, Minds, and the Problem of Macro-Objects
  Journal of Physics: Conference Series, HAPP 10th Anniversary Volume, forthcoming

Description pending.

Published

• "Prime Matter Revisited”
  in
 Thomism Revisited, edited by Gavin Kerr, Cambridge University Press, forthcoming

Description pending.

• "Saving the Macroscopic” with S. Horsley
  in
 God and the Book of Nature: Experiments in Theology of Science, edited by Mark Harris, Routledge, 2023

It is often supposed that modern physics is inconsistent with theological doctrines that assume the existence of macroscopic entities which act according to certain ends. The aim of this paper is to alleviate the appearance of tension between these theological doctrines and modern physics by considering practices in which physicists engage in implicitly teleological forms of explanation and by exploring a recent ‘contextual’ interpretation of quantum physics which can be understood in terms of an updated version of hylomorphism. We briefly consider some theological implications of this hylomorphic approach to quantum theory for ecotheology, the incarnation, and miracles.

• “Toppling the pyramids: physics without physical state monism”,
  with S. Horsley in
Time, Powers and Free Will, A. Marmodoro, C. Austin, A. Roselli, Eds., Springer, 2022

Realist philosophers of science frequently take it for granted that there is some state of the world described by our best physics such that all facts about the world, including modal and nomological facts, are determined by (or supervene upon) this total physical state -- from the 'bottom up'. We question whether this assumption is really justified in two ways: first, by considering how successful physical theories explain things in practice; secondly, by highlighting a role for 'top down' causation in physics in the boundary conditions of physical systems.  #Quantum-Forces  #Quantum-Powers

• "Cosmic hylomorphism vs Bohmian dispositionalism: implications of the ‘no-successor problem’”
  with J. Pemberton, in
 Quantum Mechanics and Fundamentality: Naturalizing Quantum Theory between Scientific Realism and Ontological Indeterminacy, Springer, 2022

The primitive ontology approach to Bohmian mechanics seeks to account for quantum phenomena in terms of particles that follow continuous trajectories and a law of nature that describes their temporal development. This approach is compatible with a dispositional account of the wave function which explains the temporal development of the particles in terms of causal powers. We argue that models which posit powers that are stimulated according to the instantaneous configuration of the particles and which manifest an instantaneous velocity profile, however, are subject to a ‘no-successor dilemma’: either time must be discrete rather than continuous, or the powers fail to determine the particles’ trajectories. What is needed is for the powers to manifest a teleological process, where this process is metaphysically prior to their instantaneous configurations.  #Quantum-Powers #Hylomorphism

• “From Quantum Physics to Classical Metaphysics”
  in 
Neo-Aristotelian Metaphysics and the Theology of Nature, Routledge, 2021, 21-65

Although the philosophy of the Middle Ages was far from monolithic, medieval metaphysics from the thirteenth century can be broadly characterised within the Latin tradition by its explicit commitment to Aristotle’s hylomorphic analysis of substances in terms of ‘matter’ (hyle) and ‘form’ (morphe). The widespread abandonment of hylomorphism in the course of the sevententh century, however, laid the foundation for a microphysicalist conception of nature, which displaced mind and agency from the natural world. I argue that the Quantum Revolution in physics has created the possibility for a rehabilitation of hylomorphism, sketching hylomorphic interpretations of both the Bohmian interpretation of quantum mechanics and the recent ‘contextual wave function collapse theory’ proposed by Barbara Drossel and George Ellis.  #Quantum-Powers #Hylomorphism

• “Reflections on science, theology and the new Aristotelianism”
  with R. Koons & J. Orr in
 Neo-Aristotelian Metaphysics and the Theology of Nature, Routledge, 2021, 1-18

The philosophical framework built by the later Plato, Aristotle, and his successors at the Lyceum, together with the great philosophers of late antiquity (the Neo-Platonists) and the High Middle Ages (Christian, Jewish, and Islamic), has endured for so long and through so many intellectual revolutions as to earn the sobriquet of ‘the perennial philosophy.’ We consider the resurgence of Aristotelian concepts, theses, and explanations which has taken place in the late twentieth- and early twenty-first-century philosophy, and their far-reaching implications for philosophical theology and the discipline of analytic theology.

• “Half-Baked Humeanism”
  in Neo-Aristotelian Perspectives on Contemporary Science,
 Routledge, 2017, 123-145

Toby Handfield has advanced a Humean form of dispositionalism that purports to reconcile the concept of causal powers with broadly Humean convictions by dissolving the requirement for objectively modal relations between powers and their manifestations. He suggests we should identify manifestations with certain types of causal processes, and identify powers with properties that are parts of their structures. I question whether causal processes can be isolated in quantum physics in the way that Handfield's form of dispositionalism requires. #Quantum-Powers

• “Reflections on contemporary science and the new Aristotelianism”
  with
 R.C. Koons and N.J. Teh, in Neo-Aristotelian Perspectives on Contemporary Science,
 Routledge, 2017, 1-11

A recent revival in (neo-)Aristotelian philosophy is beginning to transform the landscape of contemporary analytic philosophy: ethics, metaphysics, and the philosophy of science are already feeling its influence. We suggest five criteria for something being 'neo-Aristotelian' and consider a number of steps to be taken in bringing this revolution to the sciences of physics, biology, and psychology. #Quantum-Powers #Hylomorphism

• “Knowing nature: beyond reduction and emergence”
  in Knowing Creation, Eds. A. Torrance, T. McCall, Zondervan, 2017, 237-260

Since the rise of corpuscularianism, hylomorphism has been tainted with an aura of unscientific obscurantism. I argue that this stigma is an historical contingency: the notion of form that was abandoned in the seventeenth century differed significantly from the classical conception of hylomorphism that was championed by Aquinas, and the simplistic reductionism of the early mechanists who rejected it is no longer tenable. I consider the prospects for rehabilitating a more classical conception of hylomorphism in the light of contemporary science and suggest it affords a viable alternative to emergentist ontologies. #Quantum-Powers #Hylomorphism

• “Casimir forces at the cutting edge”
  with U. Leonhardt, R. Decca, S.Y. Buhmann in 
Forces of the Quantum Vacuum: an introduction to Casimir Physics, W. Simpson,
U. Leonhardt, Eds., World Scientific, 2015, 227-43

Casimir forces are emergent quantum forces that arise between macroscopic bodies. It is often assumed that scientists have got the theory of 'the Casimir effect' pretty much figured out. Well, they haven't, and physics only thrives when people ask questions. We discuss several examples of fundamental problems that have been exercising physicists at the 'cutting edge' of the Casimir community raise a number of questions about the theory of the Casimir effect.   #Quantum-Forces

In Progress

• Divine Causation and E. J. Lowe’s Analysis of Physical Causal Closure
  with Matthew Owen, invited for Routledge volume, E.J. Lowe’s Metaphysics & Philosophical Theology

Description pending.

• Natural Law and the New Aristotelianism
  with Daniel De Haan, invited for CUP volume, A History of Natural Law

Description pending.

Published

• “The Undivided Self: Aristotle and the Mind-Body Problem, by David Charles”
  forthcoming in Ancient Philosophy Today: Dialogoi

Description pending.

• “Reconsidering Causal Powers: Historical and Conceptual Perspectives, edited by 
H. Lagerlund, B. Hill, S. Psillos”
  British Journal for the History of Philosophy, 2021

Description pending.

• “Emergence. Towards a New Metaphysics and Philosophy of Science by Mariusz Tabaczek”
  The Thomist: A Speculative Quarterly Review 85 (1), 159-163

Description pending.

In Progress

• “The History of Hylomorphisted, edited by David Charles”
  invited by Notre Dame P

Description pending.