This book concerns the foundations of epistemic modality and hyperintensionality and their applications to the philosophy of mathematics. I examine the nature of epistemic modality, when the modal operator is interpreted as concerning both apriority and conceivability, as well as states of knowledge and belief. The book demonstrates how epistemic modality and hyperintensionality relate to the computational theory of mind; metaphysical modality and hyperintensionality; the types of mathematical modality and hyperintensionality; to the epistemic status of large cardinal axioms, undecidable propositions, (...) and abstraction principles in the philosophy of mathematics; to the modal and hyperintensional profiles of the logic of rational intuition; and to the types of intention, when the latter is interpreted as a hyperintensional mental state. Chapter \textbf{2} argues for a novel type of expressivism based on the duality between the categories of coalgebras and algebras, and argues that the duality permits of the reconciliation between modal cognitivism and modal expressivism. I also develop a novel topic-sensitive truthmaker semantics for dynamic epistemic logic, and develop a novel dynamic two-dimensional semantics. Chapter \textbf{3} provides an abstraction principle for epistemic (hyper-)intensions. Chapter \textbf{4} advances a topic-sensitive two-dimensional truthmaker semantics, and provides three novel interpretations of the framework along with the epistemic and metasemantic. Chapter \textbf{5} applies the fixed points of the modal $\mu$-calculus in order to account for the iteration of epistemic states in a single agent, by contrast to availing of modal axiom 4 (i.e. the KK principle). The fixed point operators in the modal $\mu$-calculus are rendered hyperintensional, which yields the first hyperintensional construal of the modal $\mu$-calculus in the literature and the first application of the calculus to the iteration of epistemic states in a single agent instead of the common knowledge of a group of agents. Chapter \textbf{6} advances a solution to the Julius Caesar problem based on Fine's `criterial' identity conditions which incorporate conditions on essentiality and grounding. Chapter \textbf{7} provides a ground-theoretic regimentation of the proposals in the metaphysics of consciousness and examines its bearing on the two-dimensional conceivability argument against physicalism. The topic-sensitive epistemic two-dimensional truthmaker semantics developed in chapters \textbf{2} and \textbf{4} are availed of in order for epistemic states to be a guide to metaphysical states in the hyperintensional setting. -/- Chapters \textbf{8-12} provide cases demonstrating how the two-dimensional hyperintensions of hyperintensional, i.e. topic-sensitive epistemic two-dimensional truthmaker, semantics, solve the access problem in the epistemology of mathematics. Chapter \textbf{8} examines the interaction between my hyperintensional semantics and the axioms of epistemic set theory, large cardinal axioms, the Epistemic Church-Turing Thesis, the modal axioms governing the modal profile of $\Omega$-logic, Orey sentences such as the Generalized Continuum Hypothesis, and absolute decidability. These results yield inter alia the first hyperintensional Epistemic Church-Turing Thesis and hyperintensional epistemic set theories in the literature. Chapter \textbf{9} examines the modal and hyperintensional commitments of abstractionism, in particular necessitism, and epistemic hyperintensionality, epistemic utility theory, and the epistemology of abstraction. I countenance a hyperintensional semantics for novel epistemic abstractionist modalities. I suggest, too, that observational type theory can be applied to first-order abstraction principles in order to make first-order abstraction principles recursively enumerable, i.e. Turing machine computable, and that the truth of the first-order abstraction principle for hyperintensions is grounded in its being possibly recursively enumerable and the machine being physically implementable. Chapter \textbf{10} examines the philosophical significance of hyperintensional $\Omega$-logic in set theory and discusses the hyperintensionality of metamathematics. Chapter \textbf{11} provides a modal logic for rational intuition and provides a hyperintensional semantics. Chapter \textbf{12} avails of modal coalgebras to interpret the defining properties of indefinite extensibility, and avails of hyperintensional epistemic two-dimensional semantics in order to account for the interaction between the interpretational and objective modalities and truthmakers thereof. This yields the first hyperintensional category theory in the literature. I invent a new mathematical trick in which first order structures are treated as categories, and Vopenka's principle can be satisfied because of the elementary embeddings between the categories and generate Vopenka cardinals while bypassing the category of Set in category theory. Chapter \textbf{13} examines modal responses to the alethic paradoxes. Chapter \textbf{14} examines, finally, the modal and hyperintensional semantics for the different types of intention and the relation of the latter to evidential decision theory. (shrink)

The A-theory of time is plagued by certain standard armchair problems: the presentism–eternalism dilemma, the problem of truth-makers, the alleged impossibility of cross-temporal relations, and the problem of temporary intrinsics. These challenges supposedly force A-theories to make incredible claims. I argue that these challenges are not deep antinomies in common sense, but rest on avoidable mistakes. Then I present a new A-theory that shows what’s possible once we move past the old problems. On this proposal, time’s passing is a metaphysically (...) fundamental aspect of reality. I take this to mean that there are fundamental facts like: four hours passed from 8am today until noon. This A-theory also posits fundamental facts about the state of the universe at a time, and about cross-temporal relationships. The proposed metaphysical package attractively articulates our common sense, pre-relativistic conception of time. (shrink)

This paper explores the metaethical ramifications of a coarse-grained criterion of property identity, sometimes referred to as Hume's dictum. According to Hume's dictum, properties are identical if and only if they are necessarily co-extensive. Assuming the supervenience of the normative on the natural, this criterion threatens the non-naturalist view that there are instantiable normative properties which are distinct from natural properties. In response, non-naturalists typically point to various counterintuitive implications of Hume's dictum. The paper clarifies this strategy and defends it (...) against objections by Bart Streumer and Ralf Bader. In addition, it is argued that proponents of naturalist and supernaturalist views, along with proponents of a certain kind of nihilism, should also reject Hume's dictum. This shows that non-naturalists can also attack the criterion indirectly, by pointing to partners in guilt. Also, it shows that not just any opponent of non-naturalism can appeal to Hume's dictum. Only certain nihilists can. (shrink)

La presencia de préstamos léxicos en una lengua es un indicio de la introducción de una palabra foránea y una nueva realidad. Aquí discutiré cómo la presencia de préstamos léxicos en las lenguas es un indicio de la pluralidad del mundo real. Para esto, tomaré la tesis expuesta por Lewis sobre la pluralidad de mundos y presentaré ejemplos del muisca y del español1, como una prueba de que el mundo, como un único lugar donde todo está incluido, conlleva la pluralidad (...) del mundo real, debido a que hay otro que suele ser desconocido y, en consecuencia, no posible dentro de sus mundos posibles. (shrink)

According to one tradition in the philosophy of language and mind, the content of a psychological attitude can be characterized by a set of possibilities. On the classic version of this account, advocated by Hintikka (1962) and Stalnaker (1984) among others, the possibilities in question are possible worlds, ways the universe might be. Lewis (1979, 1983a) proposed an alternative to this account, according to which the possibilities in question are possible individuals or centered worlds, ways an individual might be. The (...) motivation for the centered worlds theory has primarily to do with self-locating – or de se – attitudes. The focus of this paper is on the less-discussed question of how other-locating – or de re – attitudes ought to be treated within this framework. Most advocates of what we might call the modal approach to attitudes, Stalnaker and Lewis included, offer some kind of descriptivist solution to the well-known problems that other-locating attitudes raise. There are intramural differences between Stalnaker, Lewis, and other modal theorists (e.g. two-dimensionalists) on a number of issues: on the precise nature of the descriptivism involved, how attitude content relates to the asserted content of the sentences we utter, and on the proper semantic treatment of attitude reports. I pass over these differences to focus on a problem common to these various approaches: all face a problem when it comes to characterizing the contents of counterfactual attitudes like imagining, dreaming, and wishing. (shrink)

David Lewis and Peter van Inwagen have claimed that there are no “knockdown” arguments in philosophy. Their claim appears to be at odds with common philosophical practice: philosophers often write as though their conclusions are established or proven and that the considerations offered for these conclusions are decisive. In this paper, I examine some questions raised by Lewis’s and van Inwagen’s contention. What are knockdown arguments? Are there any in philosophy? If not, why not? These questions concern the nature of (...) the philosophical enterprise and our answers have implications for the limits on the attitudes of informed, rational thinkers. (shrink)

This paper aims to contribute to the analysis of the nature of mathematical modality and hyperintensionality, and to the applications of the latter to absolute decidability. Rather than countenancing the interpretational type of mathematical modality as a primitive, I argue that the interpretational type of mathematical modality is a species of epistemic modality. I argue, then, that the framework of two-dimensional semantics ought to be applied to the mathematical setting. The framework permits of a formally precise account of the priority (...) and relation between epistemic mathematical modality and metaphysical mathematical modality. The discrepancy between the modal systems governing the parameters in the two-dimensional intensional setting provides an explanation of the difference between the metaphysical possibility of absolute decidability and our knowledge thereof. I also advance a topic-sensitive epistemic two-dimensional truthmaker semantics, if hyperintensional approaches are to be preferred to possible worlds semantics. I examine the relation between two-dimensional hyperintensional states and epistemic set theory, providing two-dimensional hyperintensional formalizations of the modal logic of ZFC, large cardinal axioms, $\Omega$-logic, and the Epistemic Church-Turing Thesis. (shrink)

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. (shrink)

Robert Stalnaker has argued that mathematical information is information about the sentences and expressions of mathematics. I argue that this metalinguistic account is open to a variant of Alonzo Church's translation objection and that Stalnaker's attempt to get around this objection is not successful. If correct, this tells not only against Stalnaker's account of mathematical truths, but against any metalinguistic account of truths that are both necessary and informative.

Beach's Gaelic Symphony is plausibly an abstract object that Beach created. The view that people create some abstract objects is called abstract creationism. There are abstract creationists about many kinds of objects, including musical works, fictional characters, arguments, words, internet memes, installation artworks, bitcoins, and restaurants. Alternative theories include materialism and Platonism. This paper discusses some of the most serious objections against abstract creationism. Arguably, these objections have ramifications for questions in metaphysics pertaining to the abstract/concrete distinction, time, causation, vague (...) existence, vague identity, and inadvertent creation. (shrink)

Traditionally, perceptual experiences—for example, the experience of seeing a cat—were thought to have two quite distinct components. When one sees a cat, one’s experience is “about” the cat: this is the representational or intentional component of the experience. One’s experience also has phenomenal character: this is the sensational component of the experience. Although the intentional and sensational components at least typically go together, in principle they might come apart: the intentional component could be present without the sensational component or vice (...) versa. (shrink)

In this paper, I give an argument for the view that non-fact entities – such as physical objects, abstract objects, events and so on – can ground other entities. Roughly put, the argument is as follows: those who accept this view can provide a more plausible account of the grounds of identity facts than those who deny this view.

One conception of the Principle of Sufficient Reason maintains that every fact is metaphysically explained. There are different ways to challenge this version of the PSR; one type of challenge involves pinpointing a specific set of facts that resist metaphysical explanation. Certain identity and distinctness facts seem to constitute such a set. For example, we can imagine a scenario in which we have two qualitatively identical spheres, Castor and Pollux. Castor is distinct from Pollux but it is unclear what could (...) metaphysically explain this distinctness fact. In this paper, I argue that we should not treat identity and distinctness facts as metaphysically fundamental. As such, identity and distinctness facts do not challenge the PSR. We can metaphysically explain them. (shrink)

This paper offers a metaphysical explanation of the identity and distinctness of concrete objects. It is tempting to try to distinguish concrete objects on the basis of their possessing different qualitative features, where qualitative features are ones that do not involve identity. Yet, this criterion for object identity faces counterexamples: distinct objects can share all of their qualitative features. This paper suggests that in order to distinguish concrete objects we need to look not only at which properties and relations objects (...) instantiate but also how they instantiate these properties and relations. I propose that objects are identical when they stand in certain qualitative relations in virtue of their existence. And concrete objects are distinct when they do not stand in the same kinds of relations to one another in virtue of their existence. (shrink)

I argue for a property mereology and for mereological bundle theory. I then apply this theory to the one over many problem (universals) and puzzles concerning persistence and material constitution.

I propose formulating identity criteria as generic statements of ground, thereby avoiding objections that have been made to the more usual formulations.

We naturally think of the material world as being populated by a large number of individuals . These are things, such as my laptop and the particles that compose it, that we describe as being propertied and related in various ways when we describe the material world around us. In this paper I argue that, fundamentally speaking at least, there are no such things as material individuals. I then propose and defend an individual-less view of the material world I call (...) “generalism”. (shrink)

Recent metaphysics has turned its focus to two notions that are—as well as having a common Aristotelian pedigree—widely thought to be intimately related: grounding and essence. Yet how, exactly, the two are related remains opaque. We develop a unified and uniform account of grounding and essence, one which understands them both in terms of a generalized notion of identity examined in recent work by Fabrice Correia, Cian Dorr, Agustín Rayo, and others. We argue that the account comports with antecedently plausible (...) principles governing grounding, essence, and identity taken individually, and illuminates how the three interact. We also argue that the account compares favorably to an alternative unification of grounding and essence recently proposed by Kit Fine. (shrink)

This paper provides an overview of the history of the notion of essence in 20th century analytic philosophy, focusing on views held by influential analytic philosophers who discussed, or relied on essence or cognate notions in their works. It in particular covers Russell and Moore’s different approaches to essence before and after breaking with British idealism, the (pre- and post-)logical positivists’ critique of metaphysics and rejection of essence (Wittgenstein, Carnap, Schlick, Stebbing), the tendency to loosen the notion of logical necessity (...) to accommodate certain metaphysical truths in Wittgenstein and others, Quine’s logical rehabilitation of metaphysics and criticism of de re modality, the modal view of essence promoted by the development of quantified modal logic (C. I. Lewis, Barcan Marcus, Kripke) and direct reference theory (Barcan Marcus, Kripke, Putnam), and the emergence of the notion of metaphysical necessity (Kneale, Kripke), and finally Fine’s re-establishment of a Neo-Aristotelian, hyperintensional notion of essence in contemporary metaphysics. (shrink)

Hyperintensionality – the failure of substitutivity salva veritate of intensionally equivalent expressions – is one of the most debated topics in recent philosophy of language. Being a phenomenon that affects a wide variety of different sentential contexts, a question concerning its source arises: is hyperintensionality something that can originate from actual features of the world, or it is simply some kind of representational phenomenon, which entirely depends on our conceptual faculties and preferred semantics? After a brief general introduction to the (...) topic from the semantic standpoint, in the present work I defend a view developed by Daniel Nolan, according to which hyperintensionality can be a worldly, non-representational phenomenon. I first reconstruct Nolan’s view and argument for worldly hyperintensionality, understood through the comparison with de re intensional modality. Then, I address the main criticism that has been raised against it, developing three objections. Evidence for worldly hyperintensionality is thereby presented, by focusing on a paradigmatic trigger: counterpossible conditionals. I provide two jointly sufficient criteria for a counterpossible to be a genuine instance of worldly hyperintensionality, then illustrate three case studies from scientific practices that all rely on counterpossible reasoning: reducibility in relative computability theory; scientific explanation of certain substances’ essential properties; and emergent molecular structure in chemistry. Each of them is evaluated by checking if it satisfies the criteria for worldly hyperintensionality, leading to the detection of patterns of counterpossible dependence occurring in at least some specific instances of the case studies discussed. Finally, I suggest a possible realist reading of such dependence relation, locating its relata in the world, independently from our representations. (shrink)

This dissertation is an experiment: what happens if we treat proper names as anaphoric expressions on a par with pronouns? The first thing to notice is that a name's 'antecedent' can occur in a discourse prior to the one containing the name. An individual may be introduced and tagged with a name in one context, and then retrieved using the name in a later context. To allow for discourse crossing anaphora, in addition to the usual cross-sentential anaphora, a revision of (...) discourse semantics is in order. Essentially, we must countenance discourse referents that span contexts, and think of contexts, not as islands, but as nodes connected to each other by the discourse referents they share. Discourse semantics gives rise to a new notion of content determined by discourse reference rather than pure reference. In a space of contexts structured by shared discourse referents, discourse content becomes transmissable. For a piece of content may be sent from one context to another whenever the discourse referents bundled up in the content are held in common by the two contexts. The final step is to treat the cognitive state of an agent as just another kind of context, and so a potential recipient of discourse content. Discourse content is more fine-grained than traditional 'singular' content, and so is a better fit for our pretheoretic intuitions about communication and attitude reporting. This is illustrated by applying the theory to Frege's puzzle, a puzzle of Loar's about communication, Kripke's puzzle about belief, Geach's intentional identity and new breed of 'mixed' de re-de dicto sentence. (shrink)

The Lewisean counterpart theorist– despite not defending a genuinely essentialist view of what is possible, de re, of individuals – generally has a way to make essentialist claims come out as true, in those contexts in which they are endorsed by a committed essentialist. In this paper, I am going to show that the normal system that the Lewisean adopts when she wants to make the essentialist a truth-teller does not work with Kit Fine: his essentialist beliefs, which support his (...) counterexamples to the modal account of essentialism, cannot come out as true, in any contexts whatsoever, under the Lewisean view. After arguing that this represents a genuine problem for Lewis’s theory, I will propose a solution. I will indeed show that the Lewisean has a principled way to account for Fine’s essentialist beliefs, consistently with her own counterpart-theorist reading of them. (shrink)

The paper presents a dilemma for both epistemic and non-epistemic versions of conceivability-based accounts of modal knowledge. On the one horn, non-epistemic accounts do not elucidate the essentialist knowledge they would be committed to. On the other, epistemic accounts do not elucidate everyday life de re modal knowledge. In neither case, therefore, do conceivability accounts elucidate de re modal knowledge.

How can we acquire knowledge of metaphysical modality? How can someone come to know that he could have been elsewhere right now, or an accountant rather than a philosophy teacher, but could not have been a turnip? Jago proposes an account of a route to knowledge of the way things could have been and must be. He argues that we can move to knowledge of metaphysical modality from knowledge about essence. Curtis rejects Jago’s explanation. It cannot, he argues, explain our (...) knowledge of de re necessity. We agree. But there is more to be said. To give an account of our knowledge of metaphysical necessity is part of the task Jago set himself. But another part is to give an account of the knowledge of the possibilities accorded to particular objects. And prior to both what is needed, and something Jago attempts to supply, is an account of how ordinary knowers can come to have knowledge of an individual’s essential properties. We argue that Jago’s accounts of both these additional matters are also unsatisfactory. This is important because the thought that our knowledge of metaphysical modality has its source in our knowledge of essence is currently an attractive one and Jago has set out very clearly what must be done to justify the thought. The flaws in his proposal thus indicate the work needed if the attractive thought is to be accepted. (shrink)

I address two related questions: first, what is the best theory of how objects have de re modal properties? Second, what is the best defence of essentialism given the variability of our modal intuitions? I critically discuss several theories of how objects have their de re modal properties and address the most threatening antiessentialist objection to essentialism: the variability of our modal intuitions. Drawing on linguistic treatments of vagueness and ambiguity, I show how essentialists can accommodate the variability of modal (...) intuitions while holding that objects have their modal properties independently of contexts. (shrink)

It is commonplace to formalize propositions involving essential properties of objects in a language containing modal operators and quantifiers. Assuming David Lewis’s counterpart theory as a semantic framework for quantified modal logic, I will show that certain statements discussed in the metaphysics of modality de re, such as the sufficiency condition for essential properties, cannot be faithfully formalized. A natural modification of Lewis’s translation scheme seems to be an obvious solution but is not acceptable for various reasons. Consequently, the only (...) safe way to express some intuitions regarding essential properties is to use directly the language of counterpart theory without modal operators. (shrink)

Kit Fine famously objected against the idea that essence can be successfully analyzed in terms of de re necessity. In response, I want to explore a novel, interesting, but controversial modal account of essence in terms of intrinsicality and grounding. In the first section, I will single out two theoretical requirements that any essentialist theory should meet—the essentialist desideratum and the essentialist challenge—in order to clarify Fine’s objections. In the second section, I will assess Denby’s improved modal account, which appeals (...) to the notion of intrinsicality, and argue that it is untenable. In the third section, I will explain how, when combined with a modal-existential criterion, a hyperintensional account of intrinsicality—in the same vein as Bader (J Philos 110(10): 525–563, 2013) and Rosen (in: Hale and Hoffman (eds) Modality: Metaphysics, logic, and epistemology, Oxford, OUP, 2010)—can help successfully address Fine’s counterexamples. In the fourth section, I will evaluate how this novel analysis of essence stands with respect to sortal, origin, and natural kinds essentialism and discuss potential objections and difficulties. (shrink)

This paper outlines a heterodox and largely unexplored conception of objecthood according to which the notion of an individual object is a determinable. §1 outlines the view. §2 argues that the view is incompatible with a natural analysis of kind membership and, as a consequence, undermines the Quinean distinction between ontology and ideology. The view is then used to alleviate one source of Quinean hostility towards non-trivial restrictions on de re possibility in §3, and to elucidate Fine’s neo-Aristoteltian, non-modal conception (...) of essence in §4. §5 concludes. (shrink)

Some philosophers have argued that the vagueness exhibited by names and descriptions such as ‘Mount Everest’, ‘Downtown Manhattan’, or ‘that cloud in the sky’ is ultimately ontological: they are vague because they refer to vague objects, objects with fuzzy boundaries. I take the opposite stand and argue for the view that all vagueness is semantic. There is no such thing as a vague mountain. Rather, there are many things where we conceive the mountain to be, each with its precise boundary, (...) and when we say ‘Everest’ we are just being vague as to which thing we are referring to. This paper defends this view against some plausible objections. (shrink)

Some have argued that the vagueness exhibited by geographic names and descriptions such as ‘Albuquerque’, ‘the Outback’, or ‘Mount Everest’ is ultimately ontological: these terms are vague because they refer to vague objects, objects with fuzzy boundaries. I take the opposite stand and hold the view that geographic vagueness is exclusively semantic, or conceptual at large. There is no such thing as a vague mountain. Rather, there are many things where we conceive a mountain to be, each with its precise (...) boundary, and when we say ‘Everest’ we are just being vague as to which thing we are referring to. This paper defends this view against some plausible objections. (shrink)

Vague existence can seem like the worst kind of vagueness in the world, or seem to be an entirely unintelligible notion. This bad reputation is based upon the rumour that if there is vague existence then there are non-existent objects. But the rumour is false: the modest brand of vague existence entailed by certain metaphysical theories of composition does not deserve its bad reputation.

Nihilism is the thesis that no composite objects exist. Some ontologists have advocated abandoning nihilism in favor of deep nihilism, the thesis that composites do not existO, where to existO is to be in the domain of the most fundamental quantifier. By shifting from an existential to an existentialO thesis, the deep nihilist seems to secure all the benefits of a composite-free ontology without running afoul of ordinary belief in the existence of composites. I argue that, while there are well-known (...) reasons for accepting nihilism, there appears to be no reason at all to accept deep nihilism. In particular, deep nihilism draws no support either from the usual arguments for nihilism or from considerations of parsimony. (shrink)

Pixelism is the combination of three metaphysical thesis, namely a radical form of exdurantism, mereological nihilism and counterpart theory. Pixelism is a theory that evaluates all the metaphysical phenomena of persistence, composition and modality in a homogeneous and consistent manner. In a pixel world, there is no identity over time and over possible worlds and nothing persists over more than an instant or a world. Entities can be univocally identified by a five-coordinates system (the three spatial dimensions, the temporal one (...) and the possible worlds), and their relation is a counterpart relation both in different worlds and at different times or different regions of space. In this paper I will provide two models for pixelism: the first one takes pixels to be hypercubes, i. e. four-dimensional cubes, the acceptance of which is conditional on the acceptance of extended simples. The second one considers pixels as points in a four-dimensional space. (shrink)

This paper provides an exposition of the structuralist approach to underdetermination, which aims to resolve the underdetermination of theories by identifying their common theoretical structure. Applications of the structuralist approach can be found in many areas of philosophy. I present a schema of the structuralist approach, which conceptually unifies such applications in different subject matters. It is argued that two classic arguments in the literature, Paul Benacerraf’s argument on natural numbers and W. V. O. Quine’s argument for the indeterminacy of (...) translation, can be analyzed as instances of the structuralist schema. These two applications illustrate different kinds of conclusions that can be drawn through the structuralist approach; Benacerraf’s argument shows that we can derive an ontological conclusion about the given subject matter, while Quine’s structuralist approach leads to a semantic conclusion about how to determine linguistic meanings given radical translation. Then, as a case study, I review a recent debate in metaphysics between Shamik Dasgupta, Jason Turner, and Catharine Diehl to consider the extent to which different instances of the structuralist schema are conceptually unified. Both sides of the debate can be interpreted as utilizing the structuralist approach; one side uses the structuralist approach for an ontological conclusion, while the other side relies on a semantic conclusion. I argue that this has a strong dialectical consequence, which sheds light on the conceptual unity of the structuralist approach. (shrink)

Timelines is an inquiry into the nature of time, both as an apparent feature of the external physical world and as a fundamental feature of our experience of ourselves in the world. The principal argument of Timelines is that our coventional ideas about time are largely mistaken and that what we think of as independent physical time is actually our calibration of a certain relation between events. Namely, the relation between time-keeping events and the causal sequential differences of physical processes (...) which are real and independent of us. (shrink)

Disjointism is the view that co-located objects do not share any parts. A human-shaped statue is composed from a torso, head and limbs; the co-located lumpof clay is only composed from chunks of clay. This essay discusses the tenability of this relatively neglected view, focusing on two objections. The first objection is that disjointism implies co-located copies of microphysical particles. I argue that it doesn’t imply this and that there are more plausible disjointist views of tiny parts available. The second (...) objection is that disjointism is at a loss to explain how material objects can be co-located and why the weights of co-located objects don’t add up. The standard pluralist account appeals to the fact that co-located objects stand in mereological relations and this account is not available to the disjointist. I sketch an alternative account that appeals to a notion of ‘material identity’: the statue is taken to be the same matter as the lump of clay. The resort to a new theoretical primitive may seem to invite a quick rejection on grounds of unnecessary theoretical complexity but I argue that an abductive comparison with rival forms of pluralism shows that such a rejection is misguided. (shrink)

Magnetism in meta-semantics is the view that the meaning of our words is determined in part by their use and in part by the objective naturalness of candidate meanings. This hypothesis is commonly attributed to David Lewis, and has been put to philosophical work by Brian Weatherson, Ted Sider and others. I argue that there is no evidence that Lewis ever endorsed the view, and that his actual account of language reveals good reasons against it.

There is a long-standing disagreement among Branching-Time theorists. Even though they all believe that the branching representation accurately grasps the idea that the future, contrary to the past, is open, they argue whether this representation is compatible with the claim that one among many possible futures is distinguished—the single future that will come to be. This disagreement is paralleled in an argument about the bivalence of future contingents. The single, privileged future is often called the Thin Red Line. I reconstruct (...) the history of the arguments for and against this idea. Then, I propose my own version of the Thin Red Line theory which is immune to the major objections found in the literature. I argue that the semantic disagreement is grounded in distinct metaphysical presuppositions. My solution is expressed in a conceptual framework proposed by John MacFarlane, who distinguishes semantics from postsemantics. I extend his distinction and introduce a new notion of presemantics to elucidate my idea. (shrink)

This paper develops a view on which: (a) all fundamental facts are absolute, (b) some facts do not supervene on the fundamental facts, and (c) only relative facts fail to supervene on the fundamental facts.

It is uncontroversial that artifacts like statues and tables are mind-dependent. What is controversial is whether and how this mind-dependence has implications for the ontology of artifacts. I argue the mind-dependence of artifacts entails that there are no artifacts or artifact joints in the extra-mental world. In support of this claim, I argue that artifacts and artifact joints lack any extra-mental grounding, and so ought not to have a spot in a realist ontology. I conclude that the most plausible story (...) about artifacts is that they are in minds of suitably intelligent creatures, and not the extra-mental world. Artifacts and their joints are merely mental projections onto a world of ‘indifferent materials’. With this established, I show how many cases of object coincidence, the view that more than one material object can be located in the same exact region of space-time, cannot occur. (shrink)

Empiricist modal epistemologies can be attractive, but are often limited in the range of modal knowledge they manage to secure. In this paper, I argue that one such account – similarity-based modal empiricism – can be extended to also cover justification of many scientifically interesting possibility claims. Drawing on recent work on modelling in the philosophy of science, I suggest that scientific modelling is usefully seen as the creation and investigation of relevantly similar epistemic counterparts of real target systems. On (...) the basis of experiential knowledge of what is actually the case with the models, one can draw justified conclusions about what is de re possible for the target systems. (shrink)

In On What Matters, Derek Parfit enters the debate between actualists and possibilists. This debate concerns mere possibilia, possible but non-actual things such as golden mountains and talking donkeys. Roughly, possibilism says that there are such things, and actualism says that there are not. Parfit not only argues for possibilism but also argues that some self-proclaimed actualists are, in fact, unwitting possibilists. -/- I argue that although Parfit’s arguments do not fully succeed, they do highlight a tension within the frameworks (...) of many actualists. Many actualists conscript abstract objects into the role of "possible worlds" to avoid quantifying over mere possibilia. But, in doing so, actualists must quantify over mere possibilia anyway. When we alleviate this tension, a Parfit-friendly form of actualism arguably remains. This form of actualism says that while everything that exists is actual, it is also true in some sense that there are mere possibilia. (shrink)

Quantum entanglement poses a challenge to the traditional metaphysical view that an extrinsic property of an object is determined by its intrinsic properties. So structural realists might be tempted to cite quantum entanglement as evidence for structural realism. I argue, however, that quantum entanglement undermines structural realism. If we classify two entangled electrons as a single system, we can say that their spin properties are intrinsic properties of the system, and that we can have knowledge about these intrinsic properties. Specifically, (...) we can know that the parts of the system are entangled and spatially separated from each other. In addition, the concept of supervenience neither illuminates quantum entanglement nor helps structural realism. (shrink)

My aim in what follows is to expound and (if possible) resolve two problems in Spinoza’s theory of mind. The first problem is how Spinoza can accept a key premise in Descartes’s argument for dualism—that thought and extension are separately conceivable, “one without the help of the other”—without accepting Descartes’s conclusion that no substance is both thinking and extended. Resolving this problem will require us to consider a crucial ambiguity in the notion of conceiving one thing without another, the credentials (...) of Descartes’s principle that each substance has a principal attribute, and the prospect of neutral monism as a theory of the mind. The second problem is how Spinoza can maintain that each mental event is identical with some physical event (and conversely) while denying that there is ever any causal interaction between mental and physical events. If one mental event causes another and the first is identical with some physical event, must that physical event not cause the mental event? Resolving this problem will require looking into the reach of opacity in Spinoza’s philosophy and considering whether there are ever any legitimate exceptions to Leibniz’s Law. (shrink)

This paper defends an ontology of weak entity realism for homeostatic property cluster (HPC) theories of natural kinds, adapted from Bird’s (Synthese 195(4):1397–1426, 2018) taxonomy of such theories. Weak entity realism about HPC kinds accepts the existence of natural kinds. Weak entity realism denies two theses: that (1) HPC kinds have mind-independent essences, and that (2) HPC kinds reduce to entities, such as complex universals, posited only by metaphysical theories. Strong entity realism accepts (1) and (2), whereas moderate entity realism (...) accepts only (1). Given its commitment to (2), strong entity realism is more theoretically complex than weak entity realism, with little explanatory payoff. Given their commitment to (1), moderate and strong entity realisms cannot explain how the identity conditions of HPC kinds are to be straightforwardly knowable. I argue that weak entity realism avoids such epistemic difficulties. I further rebut two plausible criticisms of weak entity realism, namely that weak entity realism cannot account for quantification over kinds, and that weak entity realism cannot provide identity conditions for HPC kinds which are both scientifically useful and objective. Given the theoretical costs of strong and moderate entity realism, and weak entity realism’s adequate response to its most plausible challenges, weak entity realism about HPCs is to be preferred, especially for biological and chemical kinds. (shrink)

It is plausible that the universe exists: a thing such that absolutely everything is a part of it. It is also plausible that singular, structured propositions exist: propositions that literally have individuals as parts. Furthermore, it is plausible that for each thing, there is a singular, structured proposition that has it as a part. Finally, it is plausible that parthood is a partial ordering: reflexive, transitive, and anti-symmetric. These plausible claims cannot all be correct. We canvass some costs of denying (...) each claim and conclude that parthood is not a partial ordering. Provided that the relevant entities exist, parthood is not anti-symmetric and proper parthood is neither asymmetric nor transitive. (shrink)

As Vetter says, we are at the “beginning of the debate, not the end” (2015: 300) when it comes to evaluating her potentiality-based account of metaphysical modality. This paper contributes to this developing debate by highlighting three problems for Vetter’s account. Specifically, I begin (§1) by articulating some relevant details of Vetter’s potentiality-based view. This leads to the first issue (§2), concerning unclarity in the idea of degrees of potentiality. Similarly, the second issue (§3) raises trouble for Vetter’s proposed individuation (...) conditions for potentialities. Finally, the third issue (§4) is about apparently unmanifestable intrinsic potentialities, and suggests that there might be some deeper problems with anchoring metaphysical possibilities in concrete objects. More generally, though the issues detailed here are problematic, I do not take them to be fatal. However, they do show that, at minimum, further clarification of Vetter’s potentiality view is required. As Vetter says, we are at the “beginning of the debate, not the end” (2015: 300) when it comes to evaluating her potentiality-based account of metaphysical modality. This paper contributes to this developing debate by highlighting three problems for Vetter’s account. Specifically, I begin (§1) by articulating some relevant details of Vetter’s potentiality-based view. This leads to the first issue (§2), concerning unclarity in the idea of degrees of potentiality. Similarly, the second issue (§3) raises trouble for Vetter’s proposed individuation conditions for potentialities. Finally, the third issue (§4) is about apparently unmanifestable intrinsic potentialities, and suggests that there might be some deeper problems with anchoring metaphysical possibilities in concrete objects. More generally, though the issues detailed here are problematic, I do not take them to be fatal. However, they do show that, at minimum, further clarification of Vetter’s potentiality view is required. (shrink)