In a series of papers, Bence Nanay has recently put forward and defended a new theory of function, which he calls the ‘Modal Theory of Function’. In this article, I critically address this theory and argue that it fails to fulfill some key desiderata that a satisfactory theory of function must comply with. As a result, I conclude that, whatever property Nanay’s notion of function refers to, it is not the property having the function that (...) is standardly attributed in science. (shrink)

The function of a trait token is usually defined in terms of some properties of other (past, present, future) tokens of the same trait type. I argue that this strategy is problematic, as trait types are (at least partly) individuated by their functional properties, which would lead to circularity. In order to avoid this problem, I suggest a way to define the function of a trait token in terms of the properties of the very same trait token. To able to (...) allow for the possibility of malfunctioning, some of these properties need to be modal ones: a function of a trait is to do F just in case its doing F would contribute to the inclusive fitness of the organism whose trait it is. Function attributions have modal force. Finally, I explore whether and how this theory of biological function could be modified to cover artifact function. (shrink)

Discrimination is a central epistemic capacity but typically, theories of discrimination only use discrimination as a vehicle for analyzing knowledge. This paper aims at developing a self-contained theory of discrimination. Internalist theories of discrimination fail since there is no compelling correlation between discriminatory capacities and experiences. Moreover, statistical reliabilist theories are also flawed. Only a modal theory of discrimination is promising. Versions of sensitivity and adherence that take particular alternatives into account provide necessary and sufficient conditions on (...) discrimination. Safety in contrast is not sufficient for discrimination as there are cases of safety that are clearly instances of discrimination failure. The developed account of discrimination between objects will be extended to discrimination between kinds and between types. (shrink)

I provide an examination and comparison of modal theories for underwriting different non-modal theories of sets. I argue that there is a respect in which the `standard' modal theory for set construction---on which sets are formed via the successive individuation of powersets---raises a significant challenge for some recently proposed `countabilist' modal theories (i.e. ones that imply that every set is countable). I examine how the countabilist can respond to this issue via the use of regularity (...) axioms and raise some questions about this approach. I argue that by comparing them with the `standard' uncountabilist theory, a new approach that brings in arbitrariness rather than the strict controls of forcing is desirable. (shrink)

Modal constitution theory is one of the most influential solutions to the paradoxes of coincidence, and the problem of personal identity. It rests on three fundamental premises: common-sense objects exist; sometimes objects coincide in space; the coincidence of objects in space requires explanation. In this article, the author offers a critique of the modal theory of constitution. First, the definition of the constitution is examined and a new argument is offered that modal theory either (...) does not provide asymmetry of the constitution or leads to an infinite series of constitutive objects, unsatisfactorily extending ontology. Also, the author demonstrates that possible additions to the constitutive definition, which can make the definition sufficient for asymmetric relation, lead to additional theoretical difficulties, leading to the logical impossibility of constitution relation. Second, the author demonstrates that the theory of constitution offers an unsatisfactory theory of identity because it faces three problems: the overpopulation problem, the epistemic problem, and the personal problem. All of these considerations lead the author to conclude that modal constitution theory is not metaphysically satisfactory. (shrink)

All metaphors have the logical form “metaphorically, Fx”. “Metaphorically” is a modal operator. If “F” literally denotes the property F and metaphorically denotes the property G, “Metaphorically, Fx” says that x is G in reality because in its home world (Wx) it is F, when (1) x being F is manifest in Wx (2) it is a law of Wx that being F causes being G (3) being G in Wx is essential to x, hence it is G in (...) all possible worlds. For example, Emily Dickinson says that her life is (metaphorically) a loaded gun. This means that the entity x that in the real world is her life, is in its home‐world a loaded gun. A loaded gun is lethal, a trait x manifests in its home world. Therefore in the real world, too, where it is not a loaded gun but a life, x is lethal and, though deceptively (as a life) calm, it is truly dangerous. (shrink)

This paper investigates the prospects for a semantic theory that treats disjunction as a modal operator. Potential motivation for such a theory comes from the way in which modals embed within disjunctions. After reviewing some of the relevant data, I go on to distinguish a variety of modal theories of disjunction. I analyze these theories by considering pairs of conflicting desiderata, highlighting some of the tradeoffs they must face.

Free choice sequences play a key role in the intuitionistic theory of the continuum and especially in the theorems of intuitionistic analysis that conflict with classical analysis, leading many classical mathematicians to reject the concept of a free choice sequence. By treating free choice sequences as potentially infinite objects, however, they can be comfortably situated alongside classical analysis, allowing a rapprochement of these two mathematical traditions. Building on recent work on the modal analysis of potential infinity, I formulate (...) a modal theory of the free choice sequences known as lawless sequences. Intrinsically well-motivated axioms for lawless sequences are added to a background theory of classical second-order arithmetic, leading to a theory I call $MC_{LS}$. This theory interprets the standard intuitionistic theory of lawless sequences and is conservative over the classical background theory. (shrink)

Relative to any reasonable frame, satisfiability of modal quantificational formulae in which “= ” is the sole predicate is undecidable; but if we restrict attention to satisfiability in structures with the expanding domain property, satisfiability relative to the familiar frames (K, K4, T, S4, B, S5) is decidable. Furthermore, relative to any reasonable frame, satisfiability for modal quantificational formulae with a single monadic predicate is undecidable ; this improves the result of Kripke concerning formulae with two monadic predicates.

This paper is part of a general programme of developing and investigating particular first- order modal theories. In the paper, a modal theory of propositions is constructed under the assumption that there are genuinely singular propositions, ie. ones that contain individuals as constituents. Various results on decidability, axiomatizability and definability are established.

Philosophers and psychologists widely hold that artifact categories – just like biological categories – are individuated by their function. But recent empirical findings in psychology question this assumption. My proposal is to suggest a way of squaring these findings with the central role function should play in individuating artifact categories. But in order to do so, we need to give up on the standard account of artifact function, according to which function is fixed by design, and replace it with a (...) more context-sensitive account, according to which function attributions depend on the explanatory context and, as a result, categorization also depends on the explanatory context, just as the empirical findings from psychology suggest. I argue that the recent ‘modal theory of function’ originally proposed to explain biological function, is capable of providing such an account of artifact function. (shrink)

The veiled recession frame has served several times in the literature to provide examples of modal logics failing to have certain desirable properties. Makinson [4] was the first to use it in his presentation of a modal logic without the finite model property. Thomason [5] constructed a (rather complicated) logic whose Kripke frames have an accessibility relation which is reflexive and transitive, but which is satisfied by the (non-transitive) veiled recession frame, and hence incomplete. In Van Benthem [2] (...) the frame was an essential tool to find simple examples of incomplete logics, axiomatized by a formula in two proposition letters of degree 2, or by a formula in one proposition letter of degree 4 (the degree of a modal formula is the maximal number of nested occurrences of the necessity operator in ). In [3] we showed that the modal logic determined by the veiled recession frame is incomplete, and besides that, is an immediate predecessor of classical logic (or, more precisely, the modal logic axiomatized by the formula pp), and hence is a logic, maximal among the incomplete ones. Considering the importance of the modal logic determined by the veiled recession frame, it seems worthwhile to ask for an axiomatization, and in particular, to answer the question if it is finitely axiomatizable. In the present paper we find a finite axiomatization of the logic, and in fact, a rather simple one consisting of formulas in at most two proposition letters and of degree at most three. (shrink)

Some philosophers of fiction – most famously Jerold Levinson1 - have tried to argue that fictional narrators can never be identified with real authors. This argument relies on the claim that narration involves genuine assertion (not just the pretense of assertion that lacks truthfulness) and that real authors are not in a position to assert anything about beings on the fictional plain - given that they don’t rationally believe in their existence. This debate on the status of narrators depends on (...) the idea that fictional beings and beings in the real worlds reside, as it were, at different levels. The assumption that there is a gap separating the levels of fiction and reality serves as a rationale for the claim that real authors could not possibly be en rapport with the fictional characters that they create (e.g. entertain beliefs about them, etc.). (shrink)

This paper contains a positive development and a negative argument. It develops a theory of function loss and shows how this undermines an objection raised against the etiological theory of function in support of the modal theory of function. Then it raises two internal problems for the modal theory of function.

For Spinoza substances are of certain kinds. Spinoza captures this with the help of attributes. For example, thought and extension are infinite attributes of God‐substance. For Spinoza the essence of substance is its existence and existence is power. An important albeit difficult thing in Spinoza's conception of essence is that an expression of an essence, such as the physical reality or the mental reality, is always a full expression of the essence or power. Spinoza shared with Descartes a well‐known tenet (...) according to which thinking of the finite is posterior to thinking of the infinite. The chapter deals with a citation where Spinoza denies that God is subject to fate, and provides a rough sketch of how Spinoza tries to shape the universe in causal form. Spinoza never considers how such free acts of thought or adequate ideas, are consistent with his necessitarianism. (shrink)

Logic begins but does not end with the study of truth and falsity. Within truth there are the modes of truth, ways of being true: necessary truth and contingent truth. When a proposition is true, we may ask whether it could have been false. If so, then it is contingently true. If not, then it is necessarily true; it must be true; it could not have been false. Falsity has modes as well: a false proposition that could not have been (...) true is impossible or necessarily false; one that could have been true is merely contingently false. The proposition that some humans are over seven feet tall is contingently true; the proposition that all humans over seven feet tall are over six feet tall is necessarily true; the proposition that some humans are over seven feet tall and under six feet tall is impossible, and the proposition that some humans are over nine feet tall is contingently false. Of these four modes of truth, let us focus on necessity, plus a fifth: possibility. A proposition is possible if it is or could have been true; hence propositions that are either necessarily true, contingently true, or contingently false are possible. Notions that are similar to the modes of truth in being concerned with what might have been are called modal. Dispositions are modal notions, for example the disposition of fragility. Relatedly, there are counterfactual conditionals, for example “if this glass were dropped, it would break.” And the notion of supervenience is modal.1 But let us focus here on necessity and possibility. Modal words are notoriously ambiguous (or at least context-sensitive2). I may reply to an invitation to give a talk in England by saying “I can’t come; I have to give a talk in California the day before”. This use of “can’t” is perfectly appropriate. But it would be equally appropriate for me to say that I could cancel my talk in California (although that would be rude) and give the talk in England instead. What I cannot do is give both talks.. (shrink)

The word "modem" in the title of this book refers primarily to post-medieval discussions, but it also hints at those medieval mo dal theories which were considered modem in contradistinction to ancient conceptions and which in different ways influenced philosophical discussions during the early modem period. The me dieval developments are investigated in the opening paper, 'The Foundations of Modality and Conceivability in Descartes and His Predecessors', by Lilli Alanen and Simo Knuuttila. Boethius's works from the early sixth century belonged (...) to the sources from which early medieval thinkers obtained their knowledge of ancient thought. They offered extensive discus sions of traditional modal conceptions the basic forms of which were: (1) the paradigm of possibility as a potency striving to realize itself; (2) the "statistical" interpretation of modal no tions where necessity means actuality in all relevant cases or omnitemporal actuality, possibility means actuality in some rel evant cases or sometimes, and impossibility means omnitemporal non-actuality; and (3) the "logical" definition of possibility as something which, being assumed, results in nothing contradic tory. Boethius accepted the Aristotelian view according to which total possibilities in the first sense must prove their met tle through actualization and possibilities in the third sense are assumed to be realized in our actual history. On these presump tions, all of the above-mentioned ancient paradigms imply the Principle of Plenitude according to which no genuine possibility remains unrealized. (shrink)

JAAKKO HINTIKKA GAPS IN THE GREAT CHAIN OF BEING: AN EXERCISE IN THE METHODOLOGY OF THE HISTORY OF IDEAS* For some historians, to understand everything is to pardon everything. For others, like Lord Acton, history is not only a judge, ...

This paper motivates and develops a novel semantic framework for deontic modals. The framework is designed to shed light on two things: the relationship between deontic modals and substantive theories of practical rationality and the interaction of deontic modals with conditionals, epistemic modals and probability operators. I argue that, in order to model inferential connections between deontic modals and probability operators, we need more structure than is provided by classical intensional theories. In particular, we need probabilistic structure that interacts directly (...) with the compositional semantics of deontic modals. However, I reject theories that provide this probabilistic structure by claiming that the semantics of deontic modals is linked to the Bayesian notion of expectation. I offer a probabilistic premise semantics that explains all the data that create trouble for the rival theories. (shrink)

Provisional draft, pre-production copy of my book “The Modal Future” (forthcoming with Cambridge University Press).

We reply to various arguments by Otavio Bueno and Edward Zalta (‘Object Theory and Modal Meinongianism’) against Modal Meinongianism, including that it presupposes, but cannot maintain, a unique denotation for names of fictional characters, and that it is not generalizable to higher-order objects. We individuate the crucial difference between Modal Meinongianism and Object Theory in the former’s resorting to an apparatus of worlds, possible and impossible, for the representational purposes for which the latter resorts to (...) a distinction between two kinds of predication, exemplification and encoding. We show that encoding has fewer forerunners in the history of philosophy than Bueno and Zalta want, and that there’s a reason why the notion has been found baffling by some. (shrink)

Philosophical debate about the meaning of normative terms has long been pulled in two directions by the apparently competing ideas: (i) ‘ought’s do not describe what is actually the case but rather prescribe possible action, thought, or feeling, (ii) all declarative sentences deserve the same general semantic treatment, e.g. in terms of compositionally specified truth conditions. In this paper, I pursue resolution of this tension by rehearsing the case for a relatively standard truth-conditionalist semantics for ‘ought’ conceived as a necessity (...) modal and proposing a revision to it motivated by the distinctively prescriptive character of some deontic modals. In my view, this puts pressure on a popular conception of one of the core debates of metanormative theory between realists and antirealists. To make good on this claim, I go on to explore two very general ways we might interpret the results of compositional semantics—“representationalism” and “inferentialism”—in order to argue that, contrary to what is generally assumed, both can capture the special prescriptivity of ‘ought’ and both can countenance compositionally specified and informative truth-conditions for ought-sentences. Hence, my main thesis is that the deciding factor between them should not be which of ideas (i) and (ii) we are more impressed by but rather what we think of the relative merits of how representationalism and inferentialism respect these ideas. I’m inclined to favor an antirealist form of inferentialism, but the task I’ve set myself here is mainly to articulate the view in the context of metanormative theory and the semantics of deontic modals rather than try to defend it fully. To this purpose, towards the end I also briefly compare and contrast inferentialism with a third “ideationalist” metasemantic view, which may be an attractive home for some sophisticated versions of metanormative expressivism. Depending on how expressivism is worked out, it may be completely compatible with and so perhaps usefully combined with inferentialism or it may offer a competing way to respect ideas (i) and (ii). (shrink)

It is a commonsense thesis that unactualized possibilities are not parts of actuality. To keep his modal realism in line with this thesis, David Lewis employed his indexical account of the term “actual.” I argue that the addition of counterpart theory to Lewis’s modal realism undermines his strategy for respecting the commonsense thesis. The case made here also reveals a problem for Lewis’s attempt to avoid haecceitism.

In the last 30 years there has been growing interest in and a greater appreciation of the unique contributions that medieval authors have made to the history of logic. In this thesis, we compare and contrast the modal logics of Robert Kilwardby and John Buridan and explore how their two conceptions of modality relate to and differ from modern notions of modal logic. We develop formal reconstructions of both authors' logics, making use of a number of different formal (...) techniques. In the case of Robert Kilwardby we show that using his distinction between per se and per accidens modalities, he is able to provide a consistent interpretation of the apodictic fragment of Aristotle's modal syllogism and that, by generalising this distinction to hypothetical construction, he can develop an account of connexive logic. In the case of John Buridan we show that his modal logic is a natural extension of the usual Kripke-style possible worlds semantics, and that this modal logic can be shown to be sound and complete relative to a proof-theoretic formalisation of Buridan's treatment of the expository syllogism. (shrink)

In this paper, we compare two theories, modal Meinongianism and object theory, with respect to several issues that have been discussed recently in the literature. In particular, we raise some objections for MM, undermine some of the objections that its defenders raise for OT, and we point out some virtues of the latter with respect to the former.

The concept of God is studied using the ontological argument of Anselm of Canterbury that proves God’s existence using a syllogism based on ontology. Unlike metaphysical arguments that demonstrate the existence of God through the study of being and its attributes, the ontological argument aims to reach this same goal based on a concept of God by means of the idea of an entity “greater than anything that can be conceived”. Descartes’ influence highlighted some of the philosophical difficulties with the (...) inherent dualism implicit in ontology. Logic does not say whether ideas are true or false, as Logic is concerned with right or wrong inference. We take a non-dualist approach in contrast to some of the approaches reviewed. To investigate belief and faith, a modal logical formalization is used, especially modal logic S5, which we find appropriate for presenting arguments. While mathematics and logic can convince, they do not help one to believe in God. This can make us think that reason is not enough to accept God, one must have faith to have access to Him. The relation between reason and faith needs clarification, and the ontological argument requires an unsustainable dualism. (shrink)

Say that the Moving Spotlight Theory (MST) combines the following three theses: A-THEORY : There is an absolute distinction between present and non-present time.

Modal Homotopy Type Theory: The Prospect of a New Logic for Philosophy provides a reasonably gentle introduction to this new logic, thoroughly motivated by intuitive explanations of the need for all of its component parts, and illustrated through innovative applications of the calculus.

This monograph articulates and defends a theory-based epistemology of modality (TEM). According to TEM, someone justifiably believe an interesting modal claim if and only if (a) she justifiably believes a theory according to which that claim is true, (b) she believes that claim on the basis of that theory, and (c) she has no defeaters for her belief in that claim. The book has two parts. In the first, the author motivates TEM, sets out the view (...) in detail, and defends it against a number of objections. In the second, the author considers whether TEM is worth accepting. To argue that it is, the author sets out criteria for choosing between modal epistemologies, concluding that TEM has a number of important virtues. However, the author also concedes that TEM is cautious: it probably implies that we are not justified in believing some interesting modal claims that we might take ourselves to be justified in believing. This raises a question about TEM's relationship to Peter van Inwagen's modal skepticism, which the author explores in detail. As it turns out, TEM offers a better route to modal skepticism than the one that van Inwagen provides. But rather than being a liability, the author argues that this is a further advantage of the view. Moreover, he argues that other popular modal epistemologies do not fare better: they cannot easily secure more extensive modal justification than TEM. The book concludes by clarifying TEM’s relationship to the other modal epistemologies on offer, contending that TEM need not be a rival to those views, but can instead be a supplement to them. (shrink)

We have some justified beliefs about modal matters. A modal epistemology should explain what’s involved in our having that justification. Given that we’re realists about modality, how should we expect that explanation to go? In the first part of this essay, I suggest an answer to this question based on an analogy with games. Then, I outline a modal epistemology that fits with that answer. According to a theory-based epistemology of modality, you justifiably believe that p (...) if you justifiably believe a theory that says that p and you believe p on the basis of that theory. (shrink)

In this paper, I argue that not only is metaphysical modal normativism an attractive view but that, as a matter of fact, many of us have, all along, been metaphysical modal normativists of a particular stripe. Namely, we have been the kinds of modal normativists, in the form of counterpart theorists, who are robust realists about possibility simpliciter. Having introduced modal normativism as Thomasson does in Norms and Necessity, I go on to recast it in somewhat (...) different terms. With this re-casting in place we can see that while the view offers a pleasingly deflationary account of metaphysical necessity and possibility it does so only against the backdrop of robust realism about possibility simpliciter. If that is right, then Lewis’ counterpart theory turns out to be a potent version of metaphysical modal normativism. So many of us have, all along, been metaphysical modal normativists, and so much the better for it. (shrink)

Two views of game theory are discussed: (1) game theory as a description of the behavior of rational individuals who recognize each other’s rationality and reasoning abilities, and (2) game theory as an internally consistent recommendation to individuals on how to act in interactive situations. It is shown that the same mathematical tool, namely modal logic, can be used to explicitly model both views.

Recently, some authors – call them Reformists – have argued that the traditional Presentism-Eternalism and Actualism-Possibilism debates in the metaphysics of time and modality respectively are unclear or insubstantial, and should therefore give way to the newer Temporaryism-Permanentism and Contingentism- Necessitism debates. In ‘On characterising the presentism/eternalism and actualism/possibilism debates’ (2016, Analytic Philosophy 57: 110-140), Ross Cameron defends the Conservative position that the traditional debates are both substantial and distinct from the Temporaryism-Permanentism and Contingentism- Necessitism debates. In this paper I (...) provide a Reformist response to Cameron’s arguments. (shrink)