This dissertation concerns the foundations of epistemic modality. 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 dissertation demonstrates how phenomenal consciousness and gradational possible-worlds models in Bayesian perceptual psychology relate to epistemic modal space. The dissertation demonstrates, then, how epistemic modality relates to the computational theory of mind; metaphysical modality; deontic modality; logical modality; the types of mathematical modality; to the (...) epistemic status of undecidable propositions and abstraction principles in the philosophy of mathematics; to the apriori-aposteriori distinction; to the modal profile of rational propositional intuition; and to the types of intention, when the latter is interpreted as a modal mental state. Examining the nature of epistemic logic itself, I develop a novel approach to conditions of self-knowledge in the setting of the modal μ-calculus, as well as novel epistemicist solutions to Curry's, the liar, and the knowability paradoxes. Solutions to previously intransigent issues concerning the first-person concept; the distinction between fundamental and derivative truths; and the unity of intention and its role in decision theory, are developed along the way. (shrink)

When attempting to determine which of our acts affect future generations and which affect the identities of those who make up such generations, accounts of personal identity that privilege psychological features and person affecting accounts of morality, whilst highly useful when discussing the rights and wrongs of acts relating to extant persons, seem to come up short. On such approaches it is often held that the intuition that future persons can be harmed by decisions made prior to their existence is (...) mistaken as identity is a most fragile thing with even the smallest differences in the conditions under which we procreate affecting not the interests of distinct future persons, but the identities of those who will come to exist in the future. Within this paper I reject this view, holding that a subscription to these two accounts need not result in the conclusion that virtually all acts relating to possible persons are permitted. Further, I argue that such accounts may in fact allow a great deal more scope for the determination of prenatal harms than accounts of personal identity that privilege physical features. Finally, by interpreting claims regarding causal identity such as Parfit’s Time Dependence Claim in terms of Counterpart Theory I suggest that a solution to the non-identity problem can be found in the acceptance of, as relevant in prenatal cases, three kinds of objective similarity relations: Biological, Environmental and Decisional counterpart relations. (shrink)

This paper explains and defends the idea that metaphysical necessity is the strongest kind of objective necessity. Plausible closure conditions on the family of objective modalities are shown to entail that the logic of metaphysical necessity is S5. Evidence is provided that some objective modalities are studied in the natural sciences. In particular, the modal assumptions implicit in physical applications of dynamical systems theory are made explicit by using such systems to define models of a modal temporal logic. Those assumptions (...) arguably include some necessitist principles. -/- Too often, philosophers have discussed ‘metaphysical’ modality — possibility, contingency, necessity — in isolation. Yet metaphysical modality is just a special case of a broad range of modalities, which we may call ‘objective’ by contrast with epistemic and doxastic modalities, and indeed deontic and teleological ones (compare the distinction between objective probabilities and epistemic or subjective probabilities). Thus metaphysical possibility, physical possibility and immediate practical possibility are all types of objective possibility. We should study the metaphysics and epistemology of metaphysical modality as part of a broader study of the metaphysics and epistemology of the objective modalities, on pain of radical misunderstanding. Since objective modalities are in general open to, and receive, natural scientific investigation, we should not treat the metaphysics and epistemology of metaphysical modality in isolation from the metaphysics and epistemology of the natural sciences. -/- In what follows, Section 1 gives a preliminary sketch of metaphysical modality and its place in the general category of objective modality. Section 2 reviews some familiar forms of scepticism about metaphysical modality in that light. Later sections explore a few of the many ways in which natural science deals with questions of objective modality, including questions of quantified modal logic. (shrink)

Section 1 introduces the category of objective modality, closely related to linguists’ category of circumstantial or dynamic modals, and explains metaphysical modality as its maximal element. Section 2 discusses various kinds of skepticism about modality, as in Hume and recent authors, and argues that it is illmotivated to apply such skepticism to metaphysical modality but not to more restricted objective modalities, including nomic modality. Section 3 suggests that the role of counterfactual conditionals in applications of scientific theories involves an objective (...) modal dimension. Section 4 briefly discusses the role of objective probabilities in scientific theories as exemplifying the scientific study of objective modality. Section 5 summarizes a case study of dynamical systems theory, widely used in natural science, as a mathematical theory whose intended applications are objectively modal, as perspicuously articulated in a language with modal and temporal operators and propositional quantification. State spaces in natural science characterize objective possibilities. Section 6 argues that, although those possibilities are usually more restricted than metaphysical possibility, their scientific study is a partial study of metaphysical possibility too. (shrink)

It is a truth universally acknowledged that a claim of metaphysical modality, in possession of good alethic standing, must be in want of an essentialist foundation. Or at least so say the advocates of the reductive-essence-first view, according to which all modality is to be reductively defined in terms of essence. Here, I contest this bit of current wisdom. In particular, I offer two puzzles—one concerning the essences of non-compossible, complementary entities, and a second involving entities whose essences are modally (...) ‘loaded’—that together strongly call into question the possibility of reducing modality to essence. (shrink)

Quine ha promovido una forma de escepticismo sobre los juicios de modalidad de re que cuestiona su función y sugiere, en consecuencia, su eliminación. Wiggins, por su parte, ha argumentado que nuestros juicios ordinarios de individuación de objetos nos comprometen con un cierto esencialismo, con la aceptación de ciertos juicios de modalidad de re. Si Wiggins tuviera razón, tendríamos una respuesta potencial al escepticismo quineano de la función. Sin embargo, en este trabajo argumento que la propuesta de Wiggins es incapaz (...) de proporcionar una respuesta satisfactoria al escepticismo quineano, pues presupone aquello mismo que está en cuestión: los compromisos esencialistas se siguen sólo de la adopción previa de otros juicios de modalidad de re cuya función está precisamente en entredicho. Asimismo, argumento que esta misma conclusión puede extraerse de la consideración de algunas otras teorías contemporáneas de la individuación, similares a la de Wiggins. (shrink)

If the wedding had taken place an hour later, it would have been rained out. When we make counterfactual claims like this, we indicate that events are not terribly fragile things. That is, we typically think of events as particulars which can survive small changes in nearby possible worlds, such that one and the same event could have occurred under slightly different circumstances. I argue, however, that any account of “non-fragile” event individuation is subject to what is known as the (...) recycling problem. This was a problem initially raised against origin essentialism, or the view that individuals are individuated by their origins, and is roughly the difficulty that arises in cases where the criteria of individuation for a particular individual are duplicated. I then examine a potential solution, which takes its cue from predecessor essentialism, the leading response to the recycling problem in the origins literature. I argue that the predecessor essentialist’s solution yields unacceptably counter-intuitive results when applied to the recycling problem for event individuation, and conclude that, if events have qualitative individuating essences, then they must be—contrary to intuition—modally fragile entities. I then suggest three alternatives to qualitative essentialism which could accommodate our intuitions about the modal non-fragility of events. (shrink)

Several philosophers have recently suggested that truths about unactualized metaphysical possibilities are true in virtue of the existence of actual objects and their dispositional properties. For example, on this view, it is true that unicorns are metaphysically possible only if some actual object has (or had) the disposition to bring it about that there are unicorns. This view, a dispositionalist version of what has recently been dubbed “The New Actualism,” is a proposal about the nature of modal truthmakers. But, I (...) will argue, this proposal entails much more than that. Here, I will demonstrate that, if the modal truthmakers are the dispositional properties of actual objects, then either (i) there exists one or more causally potent necessary beings, or (ii) necessarily, there exists an actually infinite number of contingent beings. (shrink)

Two arguments are offered here for postulating individual essences of concrete individuals on top of their sortal essences. One is the explanatory gap argument, the other draws on the analogy with the individual essences of events presupposed in single causal explanations. These arguments support qualitative individual essences with explanatory goals as opposed to hybrid impure relational essences accounting for origin and numerical identity. It is highlighted why origin properties as parts of impure relational essences do not yield genuine de re (...) constructions. The distinction between the two types of individual essences is traced back to the ambiguity of the very notion of individuation. (shrink)

Lewis proposed to test the validity of a modal thesis by checking whether its possible-world translation is a theorem of counterpart theory. However, that criterion fails to validate many standard modal laws, thus raising doubts about the logical adequacy of the Lewisian framework. The present paper considers systems of counterpart theory of increasing strength and shows how each can be motivated by exhibiting a suitable intended model. In particular, perfect counterpart theory validates all the desired modal laws and therefore provides (...) a way out of the logical objection. Finally, a weakening of perfect counterpart theory is put forward as a response to some metaphysical objections. (shrink)

I introduce and defend the semantic notion of counterfactual identity, distinguishing it from the metaphysical notion of transworld identity. After showing that Lewis's counterpart theory misconstrues counterfactual identity facts, I outline and motivate a ‘Leibnizian counterpart theory’ where the notion of counterfactual identity is adequately modelled. Finally, I show that counterfactual identity can be characterized without relying on some implausible features of Lewis's theory of conditionals.

Realism about material objects faces a variety of epistemological objections. Recently, however, some realists have offered new accounts in response to these long-standing objections; many of which seem plausible. In this paper, I raise a new objection against realism vis-à-vis how we could empirically come to know mind-independent essential properties for objects. Traditionally, realists hold kind-membership and persistence as bound together for purposes of tracing out an object’s essential existence conditions. But I propose kind-membership and persistence for objects can conceptually (...) come apart and function epistemologically distinctly from one another—in which case the usual reliance by realists on an assumption of persistence to determine kind-membership conditions is unjustified. Thus, present realist attempts to explain how empirical detection of mind-independent essential properties for objects could possibly occur inevitably results in circularity. The charge against the realist is to explain why we don’t have to first discover persistence conditions for an object before we can ascertain kind-membership conditions for an object. If no answer is forthcoming, then it seems the weight of the epistemological objection to realism is back in full force. (shrink)

This paper argues for three kinds of possible worlds: Wittgensteinian totalities of facts, Lewisian worlds or universes, concrete objects of maximal essence, and the world, a concrete object of minimal essence. It moreover explains that correspondence truth applies to Wittgensteinian totalities and pragmatic truth to Lewisian universes. And it finally argues that this conceptualization lays proper foundations to two-dimensional semantics.

The modalities come into the world by being projections or objectivizations of our epistemic constitution. Thus this paper is a statement of Humean projectivism. In fact, it goes beyond Simon Blackburn’s version. It is also designed as a comprehensive counter-program to David Lewis’ program of Humean supervenience. In detail, the paper explains: Already the basic fact that the world is a world of states of affairs is due to the nature of our epistemic states. Objects, which figure in states of (...) affairs and which embody metaphysical modality, are constitutable by their essential properties and in fact constituted by us according to our ontological policies. What the facts are, to which the correspondence notion of truth refers, is determined by applying an epistemic or pragmatic notion of truth to the world. Causation is a specific objectivization of our conditional beliefs. Nomicity is a ‘habit of belief’, a specific way of generalizing epistemic attitudes. This covers the basic metaphysical and natural modalities. The paper attempts to convey that talking of projection or objectivization is not just imagery, but a constructively realizable program. (shrink)

Abstract: The natural lottery is a metaphor about the way luck affects the allocation of personal attributes, talents, skills, and defects. Susan Hurley has argued that it is incoherent to regard individual essential properties (IEPs) as a matter of lottery luck. The reason is that a lottery of identity-affecting properties generates the ‘non-identity problem’. For this reason among others she suggests substituting lottery luck with ‘thin luck’, i.e. luck as non-responsibility, which would allow us to coherently regard IEPs as a (...) matter of luck.I argue that we are not not-responsible for our IEPs. Therefore, the coherent range of ‘thin luck’ is not broader than that of lottery luck. Moreover, justice theorists need to be worried about the non-identity problem only to the extent that IEPs affect life prospects and it is far from evident that they do. After addressing some connected aspects of Hurley's analysis, I discuss the type of reasons that justify seeking to expand domain of justice and the ways of doing this, for instance by abandoning lottery luck. I close by suggesting, however, that if Parfit's view of ‘what matters about identity’ is correct, its application to the case of identity-affecting lotteries may prove the expansion of the domain of justice superfluous, as IEPs belong to it as it is. (shrink)

Some metaphysicians believe that metaphysical modality is explainable by the essences of objects. In §II, I spell out the definitional view of essence, and in §III, a working notion of metaphysical explanation. Then, in §IV, I consider and reject five natural ways to explain necessity by essence: in terms of the principle that essential properties can't change, in terms of the supposed obviousness of the necessity of essential truth, in terms of the logical necessity of definitions, in terms of Fine's (...) logic of essence, and in terms of the theory of real definitions. I will conclude that the present evidence favours rejecting the hypothesis that modality is explainable by essence. (shrink)

According to Essentialism, an object’s properties divide into those that are essential and those that are accidental. While being human is commonly thought to be essential to Socrates, being a philosopher plausibly is not. We can motivate the distinction by appealing—as we just did—to examples. However, it is not obvious how best to characterize the notion of essential property, nor is it easy to give conclusive arguments for the essentiality of a given property. In this paper, I elaborate on these (...) issues and explore the way in which essential properties behave in relation to other related properties, like sufficient-for-existence properties and individual essences. (shrink)

Pace Necessitism – roughly, the view that existence is not contingent – essential properties provide necessary conditions for the existence of objects. Sufficiency properties, by contrast, provide sufficient conditions, and individual essences provide necessary and sufficient conditions. This paper explains how these kinds of properties can be used to illuminate the ontological status of merely possible objects and to construct a respectable possibilist ontology. The paper also reviews two points of interaction between essentialism and modal logic. First, we will briefly (...) see the challenge that arises against S4 from flexible essential properties; as well as the moves available to block it. After this, the emphasis is put on the Barcan Formula (BF), and on why it is problematic for essentialists. As we will see, Necessitism can accommodate both (BF) and essential properties. What necessitists cannot do at the same time is to continue to understanding essential properties as providing necessary conditions for the existence of individuals; against what might be for some a truism. (shrink)

Debate between Humean contingentists and anti-Humean necessitarians in the philosophy of science is ongoing. One of the most important contemporary anti-Humeans is Alexander Bird. Bird calls the particular version of Humeanism he is opposed to 'categoricalism'. In his paper (2005) and in Chapter 4 of his book (2007) Bird argues against categoricalism about properties and laws. His arguments against categoricalism about properties are intended to support the necessitarian position he calls dispositional monism. His arguments against categoricalism about laws are intended (...) to refute the contingent regularity view of laws (even in its sophisticated Lewisean version) and the nomic necessitation view of Armstrong (which involves a contingent necessitation relation). The general position Bird defends is that properties are necessarily related to the dispositions they bestow on their bearers and laws are necessary truths. I consider two of Bird's arguments against categoricalism about properties, and one of his arguments against the regularity view of laws. Maybe other arguments against categoricalism are persuasive. These, I submit, are not. (shrink)

It seems plausible to say that what changes an entity can or cannot survive depends on its persistence conditions, and that these depend, in turn, on its sortal kind. It might seem to follow that an entity cannot belong to two sortal kinds with potentially conflicting persistence conditions. Notoriously, though, this conclusion is denied by ‘contingent identity’ theorists, who hold, for example, that a permanently coincident statue and piece of clay are identical, although the persistence conditions associated with the kinds (...) statue and piece of clay are potentially conflicting. A clash with Leibniz’s Law is avoided by treating modal predicates as what Harold Noonan has called ‘Abelardian predicates’, as in the version of ‘inconstant’ counterpart theory developed by David Lewis. In addition to other difficulties, however, there is a question whether this ‘Abelardian’ theory does justice to the intuitions expressed in such statements as that the piece of clay could, while the statue could not, have survived a radical reshaping of its matter. I present an argument, which I call ‘the vacuous satisfaction argument’, for the conclusion that the theory does indeed fail to capture the significance of such de re modal statements. (shrink)

I know that I could have been where you are right now and that you could have been where I am right now, but that neither of us could have been turnips or natural numbers. This knowledge of metaphysical modality stands in need of explanation. I will offer an account based on our knowledge of the natures, or essencess, of things. I will argue that essences need not be viewed as metaphysically bizarre entities; that we can conceptualise and refer to (...) essences; and that we can gain knowledge of them. We can know about which properties are, and which properties are not, essential to a given entity. This knowledge of essence offers a route to knowledge of the ways those entities must be or could be. (shrink)

The aim of this paper is to provide a systematic account of the metaphysically important distinction between haecceitistic properties, such as being David Lewis or being acquainted with David Lewis, and qualitative properties, such as being red or being acquainted with a famous philosopher. I first argue that this distinction is hyperintensional, that is, that cointensional properties can differ in whether they are qualitative. Then I develop an analysis of the qualitative/haecceitistic distinction according to which haecceitistic properties are relational in (...) a certain sense. I argue that this analysis can capture the hyperintensionality of the qualitative/haecceitistic distinction and is generally in accordance with the use of the notion of a qualitative property in philosophical debates. (shrink)

The view that ordinary objects are composites of form and matter ("hylomorphism") can be contrasted with the more common view that ordinary objects are composed of only material parts ("matter only"). On a matter-only view the hard question is modal: which modal profile does that (statue-shaped) object have? Does it have the modal profile of a statue, a lump, a mere aggregate? On a hylomorphic view the hard question is ontological: which objects exist? Does a statue (matter-m + statue-form), a (...) lump (matter-m + lump-form), and/or a mere aggregate (matter-m + mere aggregate-form) exist? I defend a novel answer to the hard question for hylomorphism. In particular, I argue that which ordinary objects exist depends, in part, on how subjects respond to the matter they encounter. I argue that, with regard to grounding the existence and modal properties of ordinary objects, response-dependent hylomorphism is superior to both matter only views and to non-response-dependent versions of hylomorphism. (shrink)

This essay outlines an explanatory virtue of presentism: its unique ability amongst temporal metaphysics to deliver a partial explanation of the conservational character of natural laws. That explanation relies on presentism, uniquely amongst temporal metaphysics, being able to support an endurantist account of persistence. In particular, after reconsidering a former argument for endurantism entailing presentism by Merricks, a new argument for this entailment, is expounded. Before delivering the explanation of the conservational character of natural laws, a brief account of that (...) explanandum is given, followed by an elaboration of the wider significance of an explanation for the conservational character for natural laws, particularly for the dispositional essentialist project of nomic reductionism, and explaining the non-simultaneity of causation. (shrink)

A new version of the ontological argument for the existence of God is outlined and examined. After giving a brief account of some traditional ontological arguments for the existence of God, where their defects are identified, it is explained how this new argument is built upon their foundations and surmounts their defects. In particular, this version uses the resources of impossible worlds to plug the common escape route from standard modal versions of the ontological argument. After outlining the nature of (...) impossible worlds, and motivating the need for positing them, the new argument is delineated and its premises justified. It is taken for granted that the argument cannot be sound, since it would prove too much. However, its premises are all plausible, and their denial promises to have significant ramifications. Several intuitive lines of objections are then explored in order to illuminate their shortcomings. The puzzle that the argument poses is therefore not whether the argument is sound, for it clearly cannot be. Rather, it is to place pressure on its plausible premises, so some plausible account of how the argument fails can be identified, and that the devising of such an account promises to be insightful. In the process, we should gain an improved understanding of how such ontological arguments work. (shrink)

Essentialists suppose that for every individual, if that individual exists at any possible world, then necessarily that individual exemplifies some non-trivial qualitative property essential to it, as such. Anti-essentialists deny this. One important argument leveled by some anti-essentialists against essentialism takes the form of a thought experiment, one originally introduced by Roderick Chisholm, sometimes referred to as Chisholm's Paradox (CP). In this essay, I defend essentialism against CP. I begin by presenting the argument and showing how it leads to a (...) contradiction of the essentialist thesis. I then consider one of the most popular solutions to CP to date, that given by Nathan Salmon. Next, I critique Salmon's proposal and show that it is an insufficient response on behalf of the essentialist. And finally, I propose a novel solution to the paradox and discuss why it is that many metaphysician in the past have found CP plausible, despite being fallacious. (shrink)

The purpose of this thesis is to demonstrate that metaphysics is a necessary discipline -- necessary in the sense that all areas of philosophy, all areas of science, and in fact any type of rational activity at all would be impossible without a metaphysical background or metaphysical presuppositions. Because of the extremely strong nature of this claim, it is not possible to put forward a very simple argument, although I will attempt to construct one. A crucial issue here is what (...) metaphysics in fact is -- the nature of metaphysics. The conception of metaphysics which I support could be called Aristotelian, as opposed to Kantian: metaphysics is the first philosophy and the basis of all other philosophical and scientific inquiry. I will argue that this is indeed the most plausible conception of metaphysics. (shrink)