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.

This chapter focuses mainly on how possible worlds relate to the truth and falsity of modal claims (or propositions), and therefore to whether claims are necessarily true, necessarily false, possibly true, possibly false, and so on. This issue is that of modality de dicto, modality concerning propositions. But there is another type of modality, namely modality de re. This has to do with the modal status of relations between things and their properties, with whether things possess properties necessarily, (...) contingently or not even possibly. This chapter introduces the distinction between de dicto and de re necessity, and then explores different ways of making sense of de re necessity‐necessities involving particular individuals. It talks about Strong Transworld Identity, and explores how Abstractionists respond to the Leibniz's Law argument. Some metaphysicians go farther and identify what is possible with what is conceivable, or perhaps with what we are justified in believing to be possible. (shrink)

The aim of the paper is twofold: i) to give a logically explicit formulation of a slight generalization of Quine's master argument about de re modality—an argument which imposes important constraints on modal semantics, ii) to briefly present my favored account of modal locutions (especially locutions of the de re metaphysical flavor) and show how it successfully copes with Quine's argument. Though Quine made this argument so many years ago, it is still widely misunderstood, and so careful attention (...) to detail seems warranted. From what I have seen, philosophers' attitudes towards Quine's master argument fall into two kinds: i) there are those that think that the argument has no force, because it is based on some mistake (usually, something about definite descriptions), and ii) there are those that think that the argument poses some insuperable barrier to any kind of de re modality. Neither of these attitudes is justified. So, I hope to make plain along the way that a) the original version of Quine's argument is sound, b) there is a version of this same basic argument which imposes very definite constraints on any proposed account of de re "metaphysical" modality in particular, an c) there is an account that satisfies these constraints. Part 1 of the paper is concerned with laying out and discussing three versions of Quine's argument, in the service of establishing points (a) and (b). -/- In Part 2 of the paper, I briefly sketch what I take to be a very promising, and also very Quinean account of de re modality -- one that respects the constraint on modal semantics that Quine's argument reveals and comports well with the few positive remarks Quine makes, for example, in Word and Object regarding our use of modal locutions. This will put us in a position to see that the proposed account does not fly in the face of Quine's master argument. (shrink)

Accounting for our knowledge of de re modalities is probably the main reason why the proponents of modal empiricism think that their view should be preferred to modal rationalism. In this paper, I address Sonia Roca-Royes' account, which is taken to be a representative modal empiricist view, in order to show that modal empiricism faces serious problems even in explaining our knowledge of possibility de re, something which seems to be the easiest thing to (...) explain on this view. I argue that Roca-Royes' account does not prove what she claims it does, that it can hardly be articulated in a non-redundant way, and that her account of our knowledge of possibility de re can hardly be reconciled with the essentiality of origin principle, to which modal empiricists sometimes appeal while criticizing the modal rationalist account. (shrink)

Our first goal here is to show how one can use a modal language to explicate potentiality and incomplete or indeterminate domains in mathematics, along the lines of previous work. We then show how potentiality bears on some longstanding items of concern to Mark Steiner: the applicability of mathematics, explanation, and de re propositional attitudes toward mathematical objects.

Modality is standardly thought to come in two varieties: de dicto and de re. De re modality concerns the attribution of modal features to things or individuals, and enshrines a commitment to Aristotelian essentialism. This chapter considers how David Lewis's conception of de re modality fits into his overall metaphysics. The hypothesis is that the driving force behind his metaphysics in general, and his adherence to counterpart theory in particular, is the distinctly Humean thought that necessary connections between distinct (...) existences are literally unintelligible. Lewis's appeal to counterpart theory in his account of truthmakers is explicitly aimed at delivering a truthmaker principle that eschews necessary connections. Lewis's attitude towards several well‐rehearsed debates in contemporary ontology and the reasons underlying that attitude closely mirror Hume's incendiary verdict on "divinity and school metaphysics." Finally, de re modality is connected with his adherence to the doctrine of "Humean supervenience". (shrink)

In the middle of the last century, it was common to explain the notion of necessity in linguistic terms. A necessary truth, it was said, is a sentence whose truth is guaranteed by linguistic rules. Quine famously argued that, on this view, de re modal claims do not make sense. “Porcupettes are porcupines” is necessarily true, but it would be a mistake to say of a particular porcupette that it is necessarily a porcupine, or that it is possibly purple. (...) Linguistic theories of necessity fell out of favour with the publication of Kripke’s Naming and Necessity, and Quine’s arguments were put aside. In her recent book, Norms and Necessity, Amie Thomasson presents her modal normativism, which is an updated version of the mid-century theories just described. Quine’s arguments are thus relevant once again. We recapitulate Quine’s central argument, in the context of modal normativism. We then criticise Amie Thomasson’s discussion of de re modality. We finish by briefly presenting an alternative account of de re modal statements, which is compatible with modal normativism. (shrink)

Poznawalność jako modalność de re: pewne rozwiązanie paradoksu Fitcha W artykule staramy się znaleźć nowe, intuicyjne rozwiązanie paradoksu Fitcha. Twierdzimy, że tradycyjne wyrażenie zasady poznawalności opiera się na błędnym rozumieniu poznawalności jako modalności de dicto. Zamiast tego proponujemy rozumieć poznawalność jako modalność de re. W artykule przedstawiamy minimalną logikę poznawalności, w której zasada poznawalności jest ważna, ale paradoks Fitcha już nie obowiązuje. Logikę charakteryzujemy semantycznie, a także poprzez podejście aksjomatyczne i tabelaryczne.

In his book The Philosophy of Nature, Ellis presents "the new essentialism" as resting on the notions of a property, an intrinsic property, an essential property, natural necessity and possibility, a natural kind, a fixed natural kind, and a natural law. The present paper argues that the central notions in this group are susceptible of a logical analysis, Ellis's notion of natural possibility has a historical precedent in the work of Abéelard, the notion of natural possibility contains both de re (...) and de dicto elements, and Ellis's essentialist claims, when joined to any plausible definition of natural possibility, lead to inconsistency. (shrink)

I have taken the traditional problem of the seeming interdependence of identity concepts and essentialistic concepts and the attendant difficulties with circularity as a starting point in my consideration of recent attempts to provide accounts ofde re essences. Having distinguished between theories of individual and generic essences, I have shown how a linguistic device based upon a new approach to referring expressions has, perhaps, provided some advance in the understanding of individualde re essences. I have argued that, however efficacious these (...) linguistic devices may be in dealing with individual essences, they are of no help in dealing with generic essences. I considered, therefore, one of the recent attempts to use science as the arbiter ofde re essences and concluded that such attempts will not, ultimately, solve the traditional problem of circularity. That problem remains, arising in different forms to thwart different attempts to account forde re generic essences. (shrink)

Focusing on cases which involve binding into epistemic modals with definite descriptions and quantifiers, I raise some new problems for standard approaches to all of these expressions. The difficulties are resolved in a semantic framework that is dynamic in character. I close with a new class of problems about de re readings within the scope of modals.

I explain modality de re in terms of modality de dicto because there are those who feel that modality de dicto is easier to understand. I argue that the de dicto properties of what I call the kernel proposition can indicate whether x has P essentially. I then provide directions on how to determine the kernel proposition for an object x and a property P. I conclude by addressing some objections. In particular, I argue that my account is not circular (...) despite its reliance on proper names. (shrink)

This is a three paper dissertation. ;for paper 1. Quine held that quantifying into modal contexts is illegitimate. It is sometimes thought that if he is right about this, then essentialist claims make no sense. Perhaps as a consequence of this thought together with the current prominence of essentialist views, there have been two good fairly recent attacks on Quine's argument against quantifying into modal contexts: Neale's revival of Smullyan's points and Kaplan's paper "Opacity". I first argue that (...) Quine's view is not refuted by Neale or Kaplan. I next explain that nonetheless, essentialists need not surrender in the face of Quine's injunction against quantifying in. Quine's work does not rule out the intelligibility of essentialist theses; it does however issue a challenge to explain the mysterious notion of metaphysical necessity. ;Abstract for paper 2. I examine the case that has been made for origin essentialism and find it wanting. I focus on the arguments of Salmon and Forbes. Like most origin essentialists, they have been concerned to respect the intuition that slight variation in the origin of an artifact or organism is possible. But, I argue, both of their arguments fail to respect this intuition. Salmon's argument depends on a sufficiency principle for crossworld identity, which should be rejected, if---as Salmon concedes---a given artifact might have been originally made from slightly different material. Similarly, Forbes's argument succeeds only if essentially the same argument can be used to establish a claim that---by his own admission---is too strong, namely that no variation, however slight, in an organism's origin is possible. ;Abstract for paper 3. Chisholm's Paradox suggests that origin essentialism is incompatible with the view that some variation in the origin of a given thing is possible. Since the latter view is strongly supported by intuition, origin essentialists have been eager to offer solutions to the paradox. In this paper I look at three allegedly different solutions to the paradox: Forbes's, Salmon's, and Lewis's. I give new criticisms of Forbes's view and offer new defenses of what I call the "Salmon-Lewis solution". (shrink)

In the past three decades there has been a rapid development of the formal machinery for modal logic. Quantified modal logic has developed along with a semantics and model theory that is appropriate to it. With this technical development there has been relatively little discussion of what modality is all about. There are two fundamental questions that have gone unanswered. First, to what does necessity amount? Is this a new logical notion, or is it something that can be (...) further analyzed in terms of other notions that we already have at our disposal? The second question is what makes truths involving necessity true? What is their ontological grounding in the world? This essay is directed at the first of these questions. ;There are three possible reductions of metaphysical modality. First, there is the reduction suggested by the semantics for modal logic: a reduction in terms of possible worlds. Second, there is the reduction in terms of cognition. What is possible is what is conceivable. Third, there is the reduction in terms of language. Necessities arise from the structures of language and/or language use. ;I argue that none of these is successful. All of them suffer either from presupposing some form of metaphysical necessity in the reductive base, rendering them circular and not truly reductive, or they do not do justice to the modality being reduced. ;Since necessity is not reducible to any non-modal features of the world, we need to determine whether we ought to reject it as unacceptable on this basis, or whether we ought to retain it, but treat is as a new primitive that is introduced into a philosophical or logical theory. I urge the latter course is the one that we ought to take because without it too many things will likewise be deemed unacceptable. Causal necessity and explanation, normally accepted theories or knowledge and perception, logic and logical validity, and one common manner of distinguishing sets from properties will be deemed unacceptable if de re necessity is unacceptable. All of these presuppose de re metaphysical necessity in some way. I conclude that de re metaphysical necessity ought to be retained in our theory as primitive, unanalyzable notion. (shrink)

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 offer a concise critique of a recurring line of reasoning advanced by Joseph LaPorte and Samir Okasha that all modern species concepts render the view that biological organisms essentially belong to their species empirically untenable. The argument, I claim, trades on a crucial modal ambiguity that collapses the de re/de dicto distinction. Contra their claim that the continued adherence of such a view on behalf of contemporary metaphysicians stems from the latter’s ignorance of developments in modern biology, the (...) modal ambiguity reveals the need to retrain in modal metaphysics. (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 this paper I consider Saul Kripke’s famous Humphrey objection to David Lewis’s views on de re modality and argue that responses to this objection currently on the market fail to mitigate its force in any significant way.

The subject of the first section is Carnapian modal logic. One of the things I will do there is to prove that certain description principles, viz. the ''self-predication principles'', i.e. the principles according to which a descriptive term satisfies its own descriptive condition, are theorems and that others are not. The second section will be devoted to Carnapian modal arithmetic. I will prove that, if the arithmetical theory contains the standard weak principle of induction, modal truth collapses (...) to truth. Then I will propose a different formulation of Carnapian modal arithmetic and establish that it is free of collapse. Noteworthy is that one can retain the standard strong principle of induction. I will occupy myself in the third section with Carnapian epistemic logic and arithmetic. Here too it is claimed that the standard weak principle of induction is invalid and that the alternative principle is valid. In the fourth and last section I will get back to the self-predication principles and I will point to some of the consequences if one adds them to Carnapian Epistemic arithmetic. The interaction of self-predication principles and the strong principle of induction results in a collapse of de re knowability. (shrink)

I discuss one version of a puzzle about the identity of a statue with the lump of clay of which it is made. The case is one in which the statue and lump agree in all their non-modal features. While this is a favorable case for the claim that they are identical, we nonetheless have discrepant intuitions about their potentialities, which appear irreconcilable. Critical analyses are given of recent treatments by Allan Gibbard, Kit Fine, and Stephen Yablo. An ontologically (...) conservative solution to the puzzle is offered which has the following features: the statue and lump of clay are said to be identical, our discrepant modal intuitions about the statue and lump are validated, identity is necessary, and is a relation between objects, not concepts, Leibniz' Law is not constrained, only a standard modal logic and semantics is needed, and our modal logical intuitions are preserved. In part, this last consists in proving that standard modal logics have certain structural features. In addition, the proposed account allows that names have the same function in and out of modal contexts, namely just to refer. As well, it allows genuine de re modality, i.e. that things have genuine modal properties. How the account meets general concerns about de re modality and essentialism is discussed. The proposed method of solution is also shown to apply to a number of other modal puzzles. (shrink)

This is a philosophical `position paper' (html and pdf versions), starting from the observation that we have an intuitive grasp of a family of related concepts of ``possibility'', ``causation'' and ``constraint'' which we often use in thinking about complex mechanisms, and perhaps also in perceptual processes, which according to Gibson are primarily concerned with detecting positive and negative affordances, such as support, obstruction, graspability, etc. We are able to talk about, think about, and perceive possibilities, such as possible shapes, possible (...) pressures, possible motions, and also risks, opportunities and dangers. We can also think about constraints linking such possibilities. If such abilities are useful to us (and perhaps other animals) they may be equally useful to intelligent artefacts. All this bears on a collection of different more technical topics, including modal logic, constraint analysis, qualitative reasoning, naive physics, the analysis of functionality, and the modelling design processes. The paper suggests that our ability to use knowledge about ``de-re'' modality is more primitive than the ability to use ``de-dicto'' modalities, in which modal operators are applied to sentences. The paper explores these ideas, links them to notions of ``causation'' and ``machine'', suggests that they are applicable to virtual or abstract machines as well as physical machines. Some conclusions are drawn regarding the nature of mind and consciousness. (shrink)

De re modality is eliminable if there is an effective translation of all wffs into non-de re equivalents. We cannot have logical equivalence unless 'logic' has odd theses, but we can have material equivalence by banning all essences, something the nonde re facts let us do, or by giving everything such humdrum essences as self-identity and banning the more interesting ones. Eliminability cannot be got from weaker assumptions, nor independent ones of even modest generality. The net philosophical import is that, (...) quite apart from the merits of essentialism, de re language has scant utility. (shrink)

Suppose a sentence of the following form is true in a certain context: ‘Necessarily, whenever one believes that the F is uniquely F if anything is, and x is the F, one believes that x is uniquely F if anything is’. I argue that almost always, in such a case, the sentences that result when both occurrences of ‘believes’ are replaced with ‘has justification to believe’, ‘knows’, or ‘knows a priori’ will also be true in the same context. I also (...) argue that many sentences of the relevant form are true in ordinary contexts, and conclude that a priori knowledge of contingent de re propositions is a common and unmysterious phenomenon. However, because of the pervasive context-sensitivity of propositional attitude ascriptions, the question what it is possible to know a priori concerning a given object will have very different answers in different contexts. (shrink)

A priori reflection, common sense and intuition have proved unreliable sources of information about the world outside of us. So the justification for a theory of the categories must derive from the empirical support of the scientific theories whose descriptions it unifies and clarifies. We don’t have reliable information about the de re modal profiles of external things either because the overwhelming proportion of our knowledge of the external world is theoretical—knowledge by description rather than knowledge (...) by acquaintance. This undermines the traditional idea that to be an object of category C is to be an object with such- and-such characteristic possibilities of combination. But this is no loss because de re modal thought lacks utility for creatures like us. (shrink)

Modal sentences of the form "every F might be G" and "some F must be G" have a threefold ambiguity. in addition to the familiar readings "de dicto" and "de re", there is a third reading on which they are examples of the "plural de re": they attribute a modal property to the F's plurally in a way that cannot in general be reduced to an attribution of modal properties to the individual F's. The plural "de re" (...) readings of modal sentences cannot be captured within standard quantified modal logic. I consider various strategies for extending standard quantified modal logic so as to provide analyses of the readings in question. I argue that the ambiguity in question is associated with the scope of the general term 'F'; and that plural quantifiers can be introduced for purposes of representing the scope of a general term. Moreover, plural quantifiers provide the only fully adequate solution that keeps within the framework of quantified modal logic. (shrink)

Saul Kripke once noted that there is a tight connection between computation and de re knowledge of whatever the computation acts upon. For example, the Euclidean algorithm can produce knowledge of which number is the greatest common divisor of two numbers. Arguably, algorithms operate directly on syntactic items, such as strings, and on numbers and the like only via how the numbers are represented. So we broach matters of notation. The purpose of this article is to explore the (...) relationship between the notations acceptable for computation, the usual idealizations involved in theories of computability, flowing from Alan Turing’s monumental work, and de re propositional attitudes toward numbers and other mathematical objects. (shrink)

Some philosophers think that anti-realism about de re necessity entails anti-realism about the individuation and identity of objects. In this paper I address one argument for this view, due to Sidelle, according to which the only way in which a de re modal conventionalist can avoid being refuted by a well-known argument based on the contingency of conventions is by also accepting conventionalism about objects. I show that Sidelle’s argument is not successful and, in this way, I also show (...) that the combination of de re modal anti-realism and realism about objects is at least not threatened from this direction. (shrink)

The paper presents a family of propositional epistemic logics such that languages of these logics are extended by quantification over modal operators or over agents of knowledge and extended by predicate symbols that take modal operators as arguments. Denote this family by \}\). There exist epistemic logics whose languages have the above mentioned properties :311–350, 1995; Lomuscio and Colombetti in Proceedings of ATAL 1996. Lecture Notes in Computer Science, vol 1193, pp 71–85, 1996). But these logics are (...) obtained from first-order modal logics, while a logic of \}\) can be regarded as a propositional multi-modal logic whose language includes quantifiers over modal operators and predicate symbols that take modal operators as arguments. Among the logics of \}\) there are logics with a syntactical distinction between two readings of epistemic sentences: de dicto and de re. We show the decidability of logics of \}\) with the help of the loosely guarded fragment of first-order logic. Namely, we generalize LGF to a higher-order decidable loosely guarded fragment. The latter fragment allows us to construct various decidable propositional epistemic logics with quantification over modal operators. The family of this logics coincides with \}\). There are decidable propositional logics such that these logics implicitly contain quantification over agents of knowledge, but languages of these logics are usual propositional epistemic languages without quantifiers and predicate symbols :345–378, 1993). Some logics of \}\) can be regarded as counterparts of logics defined in Grove and Halpern :345–378, 1993). We prove that the satisfiability problem for these logics of \}\) is Pspace-complete using their counterparts in Grove and Halpern :345–378, 1993). (shrink)

The central topic of this article is (the possibility of) de re knowledge about natural numbers and its relation with names for numbers. It is held by several prominent philosophers that (Peano) numerals are eligible for existential quantification in epistemic contexts (‘canonical’), whereas other names for natural numbers are not. In other words, (Peano) numerals are intimately linked with de re knowledge about natural numbers, whereas the other names for natural numbers are not. In this article I am (...) looking for an explanation of this phenomenon. It is argued that the standard induction scheme plays a key role. (shrink)