Emilia Margoni

Michael Esfeld’s minimalist ontology is committed to two axioms relating to (1) distance relations that identify simple objects (permanent matter points) while (2) the distances between them change. This article scrutinizes such a conceptual strategy to determine whether it can successfully be applied to all levels of physical reality, as Esfeld contends. To do so, it explores one of his paradigmatic sources, that is, Bohmian mechanics. Two arguments are proposed. First, while Bohm’s original formulation of Bohmian mechanics and the interpretation advocated by Dürr, Goldstein & Zanghì are typically taken as mathematically equivalent, this article argues that Esfeld’s minimalist ontology does not cover the former’s ontological richness. To secure its achievement, the minimalist ontology framework needs to (i) break the equivalence between the two versions via a commitment to the nomological interpretation of the wavefunction (ii) yet attribute some kind of physical efficacy to the wavefunction as a guiding parameter for the evolution of particles living in three-dimensional space. Both requirements will be critically addressed. Second, the article shows that Esfeld’s metaphysical program is not only forced to rely on a theoretically suspicious formulation of quantum mechanics, but that more fundamental, under-development approaches in theoretical physics are way less reconcilable with its axioms, thus questioning its alleged universality.

Physics not only describes past, present, and future events but also accounts for unrealized possibilities. These possibilities are represented through the solution spaces given by theories. These spaces are typically classified into two categories: kinematical and dynamical. The distinction raises important questions about the nature of physical possibility. How should we interpret the difference between kinematical and dynamical models? Do dynamical solutions represent genuine possibilities in the physical world? Should kinematical possibilities be viewed as mere logical or linguistic constructs, devoid of a deeper connection to the structure of physical reality? This chapter addresses these questions by analyzing some of the most significant theories in physics: classical mechanics, general relativity and quantum mechanics, with a final mention to quantum gravity. We argue that only dynamical models correspond to genuine physical possibilities.

The block universe is generally considered as the metaphysical position that best accommodates the outcomes of relativistic physics. Its most consistent formulation postulates a static universe where change is not admitted. However, some of its advocates try to reconcile its basic adynamical commitments as to the nature of physical reality with certain aspects of dynamism that arise, for instance, within human experience. In this article, I first examine how some block viewers try to reconcile dynamism and adynamism. I then go on to discuss the problems that emerge while trying to make room for dynamism within the block. To this end, I clarify the meaning of adynamism and explains what it takes to eradicate dynamism through the implementation of the so-called “Langrangian schema”. Based on this analysis, I juxtapose two resolute attempts at the formulation of a thoroughly adynamical project. The first, named relational block world, aims to make the block view totally static. The second, Barbour’s early works on the implementation of a neo-Machian relational strategy, makes the point that a complete adynamism cannot be achieved within relativity and its metaphysical counterpart. The article in conclusion argues that, by dismissing four-dimensionalism and embracing three-dimensionalism, Barbour proves better at promoting an utterly static physics.

We adopt a top-down approach to agency aimed at developing a minimalist, scalable and naturalized account of it. After providing a general definition, we explore some possible extensions and refinements, domain of applicability, as well as a comparison with other recent accounts of agency, and possible objections to our proposal. With respect to what we classify as strong (such as Tononi’s) and weak (such as Rovelli’s) characterizations, our notion of agency situates itself in a middle position – our intent being precisely that of spelling out the advantages of this median account within a variety of contexts, such as the interpretation of quantum mechanics, the debate on the nature of physical laws and Bayesianism.

Process ontology is making deep inroads into the hard sciences. For it offers a workable understanding of dynamic phenomena which sits well with inquiries that problematize the traditional conception of self-standing, definite, independent objects as the basic stuff of the universe. Process-based approaches are claimed by their advocates to yield better ontological descriptions of various domains of physical reality in which dynamical, indefinite activities are prior to definite “things” or “states of things”. However, if applied to physics, a main problem comes up: the notion itself of process appears to pivot on a conception of evolution through time that is at variance with relativistic physics. Against this worry, this article advances a conception of process that can be reconciled with general relativity. It claims that, within timeless physical frameworks, a process should not be conceived as activities evolving through time. Rather, processes concern the identity that entities obtain within the broader sets of relations in which they stand. To make this case, the article homes in on one of the physical approaches that most resolutely removes time from the basic features of reality, that is, canonical quantum gravity. As a case in point, it addresses Carlo Rovelli’s Evolving Constant approach as a physical paradigm that resolutely rejects time as an absolute parameter and recasts processualism as an inquiry into how physical systems affect one another.

What is it that determines the identity of an entity? Processualism is a theoretical perspective that offers a startling answer to this question. The identity of an entity—whether human or nonhuman, animate or inanimate—depends on the set of relations in which this entity is located. And as the sets of relations are several, so are the identities that an entity can take. This article discusses this conclusion by integrating processual accounts from different fields of inquiry, such as relativistic physics and actor-network theory. According to a processual interpretation of relativistic physics, speaking of states of things is but an abstraction. For states come from the introduction of arbitrary breakups of the spacetime continuum. Therefore, processes precede states, a process being a set of relations that confers identity on a physical state. According to a processual interpretation of actor-network theory, the same holds true for actors. Again, speaking of states of actors is but an abstraction. For what really acts is heterogeneous networks. When one describes actors in isolation, one is neglecting a whole array of relations with other actors whereby that actor can act or is made to act in such and such a way. These strands of processualism come to the same conclusion as to the identity of entities. These are not characterized by individuality but by individuality: they can be differently individuated according to the set of relations one is able to take into account. The main methodological consequence is that, if one intends to describe what an entity is, knowledge of this entity—whether human or nonhuman, animate or inanimate—should be based on progressively less narrow localizations and mappings of the relations it has to other entities.