Raoni Arroyo

In this review, I specify the metametaphysical background against which Alastair Wilson’s “_The Nature of Contingency_” (Oxford University Press, 2020) should be properly understood. Metaphysics, as a philosophical discipline, is standing on thin ice. The caricature of the situation is polarized, and is often presented as follows: metaphysics is either entirely extracted from science or it is entirely independent of science. There is a recent trend that focuses on the middle ground between these extremes, searching the philosophical literature for metaphysical theories that can fill the gap, i.e., leaving metaphysics as a free discipline to produce spoils for the eventual needs of philosophers of science. We can appreciate it better with the following distinction between the tasks of ontology and metaphysics, as complementary disciplines. If, on the one hand, we understand ontology as dealing with what exists, we can somehow extract the entities that are existentially postulated by scientific theories. Metaphysics, on the other hand, would be located as an extra layer, in charge of investigating questions about the nature of the entities obtained in this “naturalized ontology”. As a tailor, Wilson adjusts a metaphysical theory in order to perfectly dress the physical and ontological nuances of Everettian quantum mechanics, thus creating a metaphysical theory that gives us intelligibility, with the concept of modality, in two areas: in quantum mechanics, and analytic metaphysics.

This paper examines whether grounding can be naturalized. We adopt a tripartite framework—Ocat (scientific catalogue of existents), Otyp (ontological types), and metaphysics (natures/modal profiles)—and show that classifying as such the relata of putative grounding claims forces a dilemma. When the relata belong to Ocat, ‘ground’ merely paraphrases logical or scientific explanatory relations already available and adds no explanatory value. When they belong to Otyp or to metaphysics, the relation floats free of empirical warrant and cannot be naturalized. Surveying canonical cases (Fine; Schaffer) and general programs (monism; ontic structural realism), we conclude that naturalistic grounds of grounding are unavailable: the notion is either otiose to the scientific discourse, adding nothing to it, or detrimental if competing with it.

In the recent literature, moderate naturalistic metaphysicians have been attempting to justify the existence of ‘free range’ analytic metaphysics by employing an analogy with pure mathematics: just as pure mathematics is justified by its potential applications to science, so too, they argue, is analytic metaphysics justified by its potential applications in philosophy of science. Employing standard textbook logical tools to evaluate analogies, we argue that the analogy doesn’t hold: there are relevant dissimilarities between the two disciplines. The grounds and domain of application of metaphysics and mathematics to science is ultimately different, and arguments intended to justify the epistemic value of metaphysics for science often presuppose its value rather than demonstrate it. This is why metaphysics is not like mathematics.

It is a widespread consensus among metaphysicians that the bundle and substratum theories are substantially different metaphysical theories of individuality. In a realist stance towards metaphysics, they cannot both track the truth when describing fundamental reality, thus they’re rival metaphysical theories. Against that consensus, Jiri Benovsky has advanced a metametaphysical thesis that they are in fact metaphysically equivalent. This paper challenges Benovsky’s equivalence thesis with two counter-arguments based on the metaphysics of quantum mechanics: quantum metaphysical indeterminacy and wavefunction realism. As we shall argue, while both substratum and bundle theories arguably fail in standard quantum mechanics, they fail in different ways. Hence, given Benovsky’s own notion of metaphysical equivalence, they are not equivalent.

It is a widespread consensus among metaphysicians that the bundle and substratum theories are substantially different metaphysical theories of individuality. In a realist stance towards metaphysics, they cannot both track the truth when describing fundamental reality, thus they’re rival metaphysical theories. Against that consensus, Jiri Benovsky has advanced a metametaphysical thesis that they are in fact metaphysically equivalent. This paper challenges Benovsky’s equivalence thesis with two counter-arguments based on the metaphysics of quantum mechanics: quantum metaphysical indeterminacy and wavefunction realism. As we shall argue, while both substratum and bundle theories arguably fail in standard quantum mechanics, they fail in different ways. Hence, given Benovsky’s own notion of metaphysical equivalence, they are not equivalent.

This article critically examines the challenges of developing a metaphysics of non-individuals in the context of quantum mechanics. It investigates the Received View, which posits that quantum entities are non-individuals, and highlights several unresolved issues. Through these challenges, it is shown that a coherent metaphysics of non-individuals remains an ongoing project. Section 2 outlines the historical motivations behind a metaphysics of non-individuals in quantum mechanics, providing insight into how physics seems to necessitate such a framework. Section 3 discusses how these motivations have been articulated in the traditional approach (referred to here as the ‘non-reflexive proposal’), which characterizes non-individuality as a failure of the identity relation to apply. Section 4 situates the problem within a broader context, extracting methodological insights and clarifying the issue. Section 5 elaborates on the challenges that a metaphysics of non-individuals must still overcome, positioning this text as a prolegomenon to future formulations of such a metaphysics grounded in quantum mechanics, and section 6 wraps it all up.

The question “what is an interpretation?” is often intertwined with the perhaps even harder question “what is a scientific theory?”. Given this proximity, we try to clarify the first question to acquire some ground for the latter. The quarrel between the syntactic and semantic conceptions of scientific theories occupied a large part of the scenario of the philosophy of science in the 20th century. For many authors, one of the two currents needed to be victorious. We endorse that such debate, at least in the terms commonly expressed, can be misleading. We argue that the traditional notion of “interpretation” within the syntax/semantic debate is not the same as that of the debate concerning the interpretation of quantum mechanics. As much as the term is the same, the term “interpretation” as employed in quantum mechanics has its meaning beyond (pure) logic. Our main focus here lies on the formal aspects of the solutions to the measurement problem. There are many versions of quantum theory, many of them incompatible with each other. In order to encompass a wider variety of approaches to quantum theory, we propose a different one with an emphasis on pure formalism. This perspective has the intent of elucidating the role of each so-called “interpretation” of quantum mechanics, as well as the precise origin of the need to interpret it.

Scientific realism is the philosophical stance that science tracks truth, in particular in its depiction of the world’s ontology. Ontologically, this involves a commitment to the existence of entities posited by our best scientific theories; metaontologically, it includes the claim that the theoretical framework itself is true. In this article, we examine wave function realism as a case study within this broader methodological debate. Wave function realism holds that the wave function, as described by quantum mechanics, corresponds to a real physical entity. We focus on a recent formulation of this view that commits to the ontology of the wave function while deliberately avoiding the metaontological question of the framework’s truth. Instead, the view is defended on pragmatic, non-truth-conductive grounds. This, we argue, raises tensions for the purported realism of wave function realism and its compatibility with scientific realism more broadly.

This article proposes a reading of quantum metaphysical indeterminacy from the perspective of Parsons' Nuclear Meinongianism. In doing so, we identify a fundamental incompatibility between a key feature of Parsons' theory and standard quantum mechanics. Our approach interprets quantum indeterminacy as property incompleteness. However, this move, when combined with Parsons' framework, leads to what we term the ``Incompleteness-Entails-Nonexistence Principle'' (IENP), which implausibly entails the nonexistence of quantum objects. For Meinongianism to be a suitable tool for the metaphysics of quantum mechanics, this principle must be addressed. We argue for dropping the IENP and discuss the resulting metaphysical and metametaphysical consequences.

There is a gap between the “non-individuals” interpretation of quantum mechanics and our world of experience. This chapter begins to bridge it. Section 9.1 states the problem with Abner Shimony’s “Phenomenological principle”; Sect. 9.2 briefly presents the interpretation with connection to standard quantum mechanics; Sect. 9.3 presents the measurement problem in connection with the Phenomenological principle, the standard way out of it, and why the “non-individuals” interpretation of quantum mechanics should not follow it; Sect. 9.4 finally shows two closed venues for such an interpretation (Bohmian mechanics and the Modal-Hamiltonian Interpretation), and two alternatives for such it (Everettian quantum mechanics and spontaneous collapse theories); Sect. 9.5 is a conclusion.

Scientific realism is, currently, one of the most well-entrenched background assumptions of some relevant versions of anti-exceptionalism about logic. We argue that this is a sort of sociological contingency rather than a metaphilosophical necessity. Drawing parallels with the metaphysics of science (as applied to quantum foundations), we try to bring the realist assumptions of anti-exceptionalism to light, to demotivate the necessary connection between realism and anti-exceptionalism, briefly exploring the possibility of adopting antirealism as the background default view of science instead.

In this review, I specify the metametaphysical background against which Alastair Wilson’s “The Nature of Contingency” (Oxford University Press, 2020) should be properly understood. Metaphysics, as a philosophical discipline, is standing on thin ice. The caricature of the situation is polarized, and is often presented as follows: metaphysics is either entirely extracted from science or it is entirely independent of science. There is a recent trend that focuses on the middle ground between these extremes, searching the philosophical literature for metaphysical theories that can fill the gap, i.e., leaving metaphysics as a free discipline to produce spoils for the eventual needs of philosophers of science. We can appreciate it better with the following distinction between the tasks of ontology and metaphysics, as complementary disciplines. If, on the one hand, we understand ontology as dealing with what exists, we can somehow extract the entities that are existentially postulated by scientific theories. Metaphysics, on the other hand, would be located as an extra layer, in charge of investigating questions about the nature of the entities obtained in this “naturalized ontology”. As a tailor, Wilson adjusts a metaphysical theory in order to perfectly dress the physical and ontological nuances of Everettian quantum mechanics, thus creating a metaphysical theory that gives us intelligibility, with the concept of modality, in two areas: in quantum mechanics, and analytic metaphysics.

In recent work, Nina Emery has defended the view that, in the context of naturalistic metaphysics, one should maintain the same epistemic attitude towards science and metaphysics. That is, naturalists who are scientific realists ought to be realists about metaphysics as well; and naturalists who are antirealists about science should also be antirealists about metaphysics. We call this the ‘parity thesis’. This paper suggests that the parity thesis is widely, albeit often implicitly, accepted among naturalistically inclined philosophers, and essentially for reasons similar to Emery’s. Then, reasons are provided for resisting Emery’s specific inference from scientific realism to realism about metaphysics. The resulting picture is a more nuanced view of the relationship between science and metaphysics within the naturalistic setting than the one which is currently most popular.

Philosophers of science commonly connect ontology and science, stating that these disciplines maintain a two-way relationship: on the one hand, we can extract ontology from scientific theories; on the other hand, ontology provides the realistic content of our scientific theories. In this article, we will critically examine the process of naturalizing ontology, i.e., confining the work of ontologists merely to the task of pointing out which entities certain theories commit themselves to. We will use non-relativistic quantum mechanics as a case study. We begin by distinguishing two roles for ontology: the first would be characterized by cataloging existing entities according to quantum mechanics; the second would be characterized by establishing more general ontological categories in which existing entities must be classified. We argue that only the first step is available for a naturalistic approach; the second step not being open for determination or anchoring in science. Finally, we also argue that metaphysics is still a step beyond ontology, not contained in either of the two tasks of ontology, being thus even farther from science.

Metaphysics is traditionally conceived as aiming at the truth — indeed, the most fundamental truths about the most general features of reality. Philosophical naturalists, urging that philosophical claims be grounded on science, have often assumed an eliminativist attitude towards metaphysics, consequently paying little attention to such a definition. In the more recent literature, however, naturalism has instead been taken to entail that the traditional conception of metaphysics can be accepted if and only if one is a scientific realist (and puts the right constraints on acceptable metaphysical claims). Here, we want to suggest that naturalists can, and perhaps should, pick a third option, based on a significant yet acceptable revision of the established understanding of metaphysics. More particularly, we will claim that a fictionalist approach to metaphysics is compatible with both the idea that the discipline inquires into the fundamental features of reality and naturalistic methodology; at the same time, it meshes well with both scientific realism and instrumentalism.

Philosophers of science commonly connect ontology and science, stating that these disciplines maintain a two-way relationship: on the one hand, we can extract ontology from scientific theories; on the other hand, ontology provides the realistic content of our scientific theories. In this article, we will critically examine the process of naturalizing ontology, i.e., confining the work of ontologists merely to the task of pointing out which entities certain theories commit themselves to. We will use non-relativistic quantum mechanics as a case study. We begin by distinguishing two roles for ontology: the first would be characterized by cataloging existing entities according to quantum mechanics; the second would be characterized by establishing more general ontological categories in which existing entities must be classified. We argue that only the first step is available for a naturalistic approach; the second step not being open for determination or anchoring in science. Finally, we also argue that metaphysics is still a step beyond ontology, not contained in either of the two tasks of ontology, being thus even farther from science.

In this article, we discuss some of the challenges related to formulating and adopting a realist position regarding non-relativistic quantum mechanics. In a standard approach to ontology, the ontological commitments of scientific theories can be extracted from them. Scientific realism is the standpoint that our best scientific theories are approximately true, and thus, their ontological commitments, roughly speaking, correspond to reality. Quantum mechanics complicates this view by introducing an interpretational requirement that links a particular conception of how reality should be to the theory. This generates comprehensive difficulties: when we separate theory and interpretation, we have a clear conception of theory but not of interpretation and how to extract its ontology. On the other hand, if we somehow identify theory and interpretation, we have a reasonably clear conception of the desired ontology but lose our best characterizations of theory, rendering our methods for extracting ontology ineffective. Our aim is to map out the challenges for future rigorous realist approaches to quantum mechanics.

According to a particular interpretation of quantum mechanics, the causal role of human consciousness in the measuring process is called upon to solve a foundational problem called the “measurement problem.” Traditionally, this interpretation is tied up with the metaphysics of substance dualism. As such, this interpretation of quantum mechanics inherits the dualist’s mind-body problem. Our working hypothesis is that a process-based approach to the consciousness causes collapse interpretation (CCCI) ---leaning on Whitehead’s solution to the mind-body problem--- offers a better metaphysical understanding of consciousness and its role in interpreting quantum mechanics. This article is the kickoff for such a research program in the metaphysics of science.

Este artigo trata de aspectos abordados aspectos históricos e filosóficos do problema da medição em mecânica quântica, com ênfase na famosa formulação de Erwin Schrödinger conhecida como o “paradoxo do Gato de Schrödinger”. Pensado para o uso em sala de aula em cursos de filosofia da ciência a nível de graduação e pós-graduação, o artigo trata, em especial: da gênese do problema da medição (§ 1); sua conexão com os debates filosóficos sobre a localidade e separabilidade (§ 2); as consequências para debates futuros na metafísica da ciência (§ 3). Palavras-chave: filosofia da mecânica quântica; gato de Schrödinger; metafísica da ciência; problema da medição; separabilidade.

Quantum mechanics is an area of Physics that deals with subatomic phenomena. It can be extracted from a vision of the physical world which contradicts many aspects of our everyday perception, prompting many philosophical debates and admitting different interpretations. Among the wide range of problems within the interpretation of quantum theory, there is the measurement problem. Some philosophical aspects of the problems concerning the notion of “measurement” in quantum mechanics are analyzed in order to identify how the problem arises in discussions about the foundations of the interpretation of quantum theory and how it holds up even in the most recent interpretations, conflicting in various ways (including ontological) with a worldview that can be drawn from classical physics – assuming that it provides a worldview. Although Bohr has, on several occasions, addressed the measurement problem, he did not get to properly formulate a measurement theory. This was done by von Neumann, who presented an axiomatic formulation of a measurement theory along with a critique of the Bohrian model and, at the same time, an alternative grounded in the introduction of a dualistic notion of consciousness (nonphysical) with causal power in quantum measurement. It is precisely the introduction of the dualistic concept of consciousness within the scope of the concept of measurement that inserts into the philosophical discussion as an ontological problem insofar as it comes to the introduction of a new entity in the universe. The first subjetivistic interpretations, proposed by London and Bauer, are analysed, passing through the solipsistic difficulty to this subjectivist interpretations placed through Wigner’s work, up to the interpretations inspired by the late work of the physicist Erwin Schrödinger, which proposes a monistic interpretation of the notion of “consciousness”. Some distinct attitudes towards measuring the philosophical problems are outlined very briefly in the form of sampling, to illustrate the plural character of the proposals for interpretation of the term “measurement” in quantum mechanics. Although strictly speaking there is no “best” interpretation of quantum mechanics, it is suggested that the formulation of an ontology that takes into account quantum mechanics could help in understanding certain concepts, such as “measurement” or “consciousness” without that philosophical difficulties – as dualism – or paradoxical situations – such as solipsism – necessarily accompany them.

This chapter argues that the general philosophy of science should learn metaphilosophical lessons from the case of metaphysical underdetermination, as it occurs in non-relativistic quantum mechanics. Section presents the traditional discussion of metaphysical underdetermination regarding the individuality and non-individuality of quantum particles. Section discusses three reactions to it found in the literature: eliminativism about individuality; conservatism about individuality; eliminativism about objects. Section wraps it all up with metametaphysical considerations regarding the epistemology of metaphysics of science.

Ever since its beginnings, standard quantum mechanics has been associated with a metaphysical view according to which the theory deals with non-individual objects, i.e., objects deprived of individuality in some sense of the term. We shall examine the grounds of the claim according to which quantum mechanics is so closely connected with a metaphysics of non-individuals. In particular, we discuss the attempts to learn the ‘metaphysical lessons’ required by quantum mechanics coming from four distinct roads: from the formalism of the theory, treating separately the case of the physics and the underlying logic; from the ontology of the theory, understood as the furniture of the world according to the theory; and, at last, we analyze whether a metaphysics of non-individuals is indispensable from a purely metaphysical point of view. We argue that neither non-individuality nor individuality is to be found imposed on us in any of these levels so that it should be seen as a metaphysical addition to the theory, rather than as a lesson from it.

In this review, I specify the metametaphysical background against which Alastair Wilson’s “The Nature of Contingency” (Oxford University Press, 2020) should be properly understood. Metaphysics, as a philosophical discipline, is standing on thin ice. The caricature of the situation is polarized, and is often presented as follows: metaphysics is either entirely extracted from science or it is entirely independent of science. There is a recent trend that focuses on the middle ground between these extremes, searching the philosophical literature for metaphysical theories that can fill the gap, i.e., leaving metaphysics as a free discipline to produce spoils for the eventual needs of philosophers of science. We can appreciate it better with the following distinction between the tasks of ontology and metaphysics, as complementary disciplines. If, on the one hand, we understand ontology as dealing with what exists, we can somehow extract the entities that are existentially postulated by scientific theories. Metaphysics, on the other hand, would be located as an extra layer, in charge of investigating questions about the nature of the entities obtained in this “naturalized ontology”. As a tailor, Wilson adjusts a metaphysical theory in order to perfectly dress the physical and ontological nuances of Everettian quantum mechanics, thus creating a metaphysical theory that gives us intelligibility, with the concept of modality, in two areas: in quantum mechanics, and analytic metaphysics.

This book discusses the philosophical work of Décio Krause. Non-individuality, as a new metaphysical category, was thought to be strongly supported by quantum mechanics. No one did more to promote this idea than the Brazilian philosopher Décio Krause, whose works on the metaphysics and logic of non-individuality are now widely regarded as part of the consolidated literature on the subject. This volume brings together chapters elaborating on the ideas put forward and defended by Krause, developing them in many different directions, commenting on aspects not completely developed so far, and, more importantly, critically addressing their current formulations and defenses by Krause himself. Given that Krause’s ideas do connect directly and indirectly with a wide array of subjects, such as the philosophy of quantum mechanics, more broadly understood, the philosophy of logic and logical philosophy, non-classical logics, metaphysics, and ontology, this volume contains important material for the research on logic and foundations of science, broadly understood. All the invited contributors have already worked with the ideas developed by Décio (some of them still work with them), being also distinct authors and extremely relevant in their areas of expertise. The volume is aimed at philosophers, including those of physics and quantum mechanics.