Why can I not appropriately utter ‘It must be raining’ while standing outside in the rain, even though every world consistent with my knowledge is one in which it is raining? The common response to this problem is to hold that epistemic must, in addition to quantifying over epistemic possibilities, carries some additional evidential information concerning the source of one'S evidence. I argue that this is a mistake: epistemic modals are mere quantifiers over epistemic possibilities. My (...) central claim is that the seeming anomaly of the data above arises from a mistaken conception of what a possibility is. Instead of conceiving of possibilities as possible worlds, I argue that we should conceive of possibilities as answers to open questions. (shrink)

Claims of the form 'I know P and it might be that not-P' tend to sound odd. One natural explanation of this oddity is that the conjuncts are semantically incompatible: in its core epistemic use, 'Might P' is true in a speaker's mouth only if the speaker does not know that not-P. In this paper I defend this view against an alternative proposal that has been advocated by Trent Dougherty and Patrick Rysiew and elaborated upon in Jeremy Fantl and (...) Matthew McGrath's recent Knowledge in an Uncertain World. (shrink)

Kripke (1980) hypothesizes a link between rigidity and scope: a singular term is rigid over a space S of possibilities just in case it is scopeless with respect to modals that quantify over S. Kripke’s hypothesis works well when we consider the interaction of singular terms with metaphysical modals, but runs into trouble when we consider the interaction of singular terms with epistemic modals. After describing the trouble in detail, and considering one non-solution to it, I develop a novel (...) version of dynamic semantics that resolves the problem. (shrink)

In “Knowledge and epistemic necessity,” John Hawthorne gives a defense of what he rightly calls the “standard approach” to epistemic possibility against what he calls a new “competing idea” presented by Dougherty and Rysiew which he notes has been “endorsed and elaborated upon” by Fantl and McGrath. According to the standard approach, roughly, p is epistemically possible for S if S doesn’t know that not-p. The new approach has it that p is epistemically possible if p has (...) a non-zero epistemic probability. Both approaches, he notes, would explain the oddness of CKAs, utterances of the form “p, but possibly not p.” However, he offers a number of arguments designed to show that the standard approach has other advantages. In this paper, we undermine Hawthorne’s reasons for favoring the standard approach over Dougherty and Rysiew’s alternative approach. (shrink)

In a recent paper, Ippolito and Farkas (Linguist Philos, 45(4):943–984, 2022b) (I &F) question the premise that Italian future is epistemic necessity; in this brief response we want to show that there is no empirical motivation for abandoning it once we employ a more flexible framework of modality such as the one advanced in Giannakidou and Mari (Linguist Philos 41(6): 623–664, 2018) (G &M) which posits a ranking meta-evaluation in the modal structure that explains the empirical objections raised (...) by I &F. We show that the core of the account in I &F shares the main ingredients with G &M and that, unlike what I &F propose, Italian future is not pure credence. (shrink)

Modal knowledge accounts like sensitivity or safety face a problem when it comes to knowing propositions that are necessarily true because the modal condition is always fulfilled no matter how random the belief forming method is. Pritchard models the anti-luck condition for knowledge in terms of the modal principle safety. Thus, his anti-luck epistemology faces the same problem when it comes to logical necessities. Any belief in a proposition that is necessarily true fulfills the anti-luck condition and, therefore, qualifies as (...) knowledge. Miščević shares Pritchard’s take on epistemic luck and acknowledges the resulting problem. In his intriguing article “Armchair Luck: Apriority, Intellection and Epistemic Luck” Miščević suggests solving the problem by supplementing safety with a virtue theoretic condition-“agent stability”-which he also spells out in modal terms. I will argue that Miščević is on the right track when he suggests adding a virtue-theoretic component to the safety condition. However, it should not be specified modally but rather in terms of performances that manifest competences. (shrink)

The necessity of origin suggests that a person’s identity is determined by the particular pair of gametes from which the person originated. An implication is that speculative scenarios concerning how we might otherwise have been had our gametic origins been different are dismissed as being metaphysically impossible. Given, however, that many of these speculations are intelligible and commonplace in the discourses of competent speakers, it is overhasty to dismiss them as mistakes. This paper offers a way of understanding these (...) speculations that does not commit them to incoherence but aims to make the best sense of what they are expressing. Using the philosophical framework of two‐dimensional semantics, it proposes that the speculative scenarios are best analysed as epistemic possibilities, rather than as metaphysical possibilities. It then explores some implications of this analysis for the ethical challenges associated with the non‐identity problem. (shrink)

Philosophers have observed that metaphysical necessity appears to be a true or real or genuine form of necessity while epistemic necessity does not. Similarly, natural necessity appears genuine while deontic necessity does not. But what is it for a form of necessity to be genuine? I defend an account of genuine necessity in explanatory terms. The genuine forms of necessity, I argue, are those that provide what I call necessitarianexplanation. I discuss (...) the relationship of necessitarian explanation to ground. (shrink)

A popular definition of epistemic peerage maintains that two subjects are epistemic peers if and only if they are equals with respect to general epistemic virtues and share the same evidence about the targeted issue. In this paper I shall take up the challenge of defending the necessity of the evidential equality condition for a definition of epistemic peerage from criticisms that can be elicited from the literature on peer disagreement. The paper discusses two definitions (...) that drop this condition and argues that they yield implausible verdicts about the instantiation of the epistemic peerage relation. (shrink)

By an incomplete sentence we shall understand a declarative sentence that can be used, without variation in its meaning, to make different statements in different contexts. Although the point deserves supporting argument, which we will not provide, sentences whose grammatical subjects are indexical expressions or demonstratives are obvious, plausible examples of incomplete sentences. Uttered in one context the sentence ‘He is ill’ may be used to make one statement, for example, that George is ill, while in another context the very (...) same sentence may be used to make a quite different statement, for example, that Paul is ill. (shrink)

I argue that the account of the epistemic modalities developed by Kripke and Putnam is incomplete since it does not make use of the possible worlds machinery that is indispensable to their analysis of the metaphysical modalities. It would have been simpler and more elegant if they had used the concept of 'possible world' to explain both modalities. Instead, they provide an explication of the epistemic modalities in terms of the vague concepts of conceivability and revisability. I show (...) that logical omniscience as a consequence of a possible worlds analysis of the epistemic modalities can be made palatable. (shrink)

Argues that that all necessity is consequent, and that reason and God are contingent, albeit eternal, necessitiesFocusing on the central striking claim that there is something rather than nothing - that all necessity is consequent - Tritten engages with a wide range of ancient as well as contemporary philosophers including Quentin Meillassoux, Richard Kearney, Friedrich Schelling, Émile Boutroux and Markus Gabriel. He examines the ramifications of this truth arguing that even reason and God, while necessary according to essence, (...) are utterly contingent with respect to existence.Key FeaturesShows how all necessary truths are products of an epistemic framework that is itself historically contingentExplains the nature of contingency as something that stems from the facticity of being itself Explains the emergence and ontological status of reason, particularly the principle of sufficient reasonArgues for the contingency of God's existence while maintaining the necessity of his essenceProvides an alternative to Quentin Meillassoux's thesis for the necessity of contingency". (shrink)

We offer an analysis of future morphemes as epistemic operators. The main empirical motivation comes from the fact that future morphemes have systematic purely epistemic readings—not only in Greek and Italian, but also in Dutch, German, and English will. The existence of epistemic readings suggests that the future expressions quantify over epistemic, not metaphysical alternatives. We provide a unified analysis for epistemic and predictive readings as epistemic necessity, and the shift between the two (...) is determined compositionally by the lower tense. Our account thus acknowledges a systematic interaction between modality and tense—but the future itself is a pure modal, not a mixed temporal/modal operator. We show that the modal base of the future is nonveridical, i.e. it includes p and ¬p worlds, parallel to epistemic modals such as must, and present arguments that future morphemes are a category that stands in between epistemic modals and predicates of personal taste. We identify, finally, a subclass of epistemic futures which are ratificational, and argue that will is a member of this class. (shrink)

In an earlier paper by the author, Åqvist , I presented an approach to the logic of historical necessity, or inevitability, in the sense of a “two-dimensional” combination of tense and modal logic for worlds, or histories, with the same time order, known as T × W logic. Distinctive features of that approach were, apart from its two-dimensionality, its being based on discrete and finite time, and its use of so-called systematic frame constants in order to enable us to (...) indicate longitudes and latitudes of any points in the co-ordinate systems under consideration. This led us to study and axiomatize an infinite hierarchy HTWxy of two-dimensional modal tense logics with the characteristic operators for historical necessity and possibility added to the original basic vocabulary. The main purpose of the present paper is then twofold: to extend the logics HTWxy to the interesting branch of philosophical logic constituted by deontic logic as combined with tense logic; and to deal with a curious puzzle known as the so-called epistemic obligation paradox – a well known stumbling-block in this area of research in philosophical logic. We argue for a solution to both these problems, which appeals to a new infinite hierarchy DHTWxym of extensions of the HTWxy in the sense of logics combining dyadic deontic modalities with temporal ones such as those for historical necessity and other two-dimensional modalities. (shrink)

Epistemic Modality Epistemic modality is the kind of necessity and possibility that is determined by epistemic constraints. A modal claim is a claim about how things could be or must be given some constraints, such as the rules of logic, moral obligations, or the laws of nature. A modal … Continue reading Epistemic Modality →.

The paper distinguishes between weak and strong epistemic possibility and argues that the notion of strong epistemic possibility is the key to solving some of the most vexing puzzles about the semantics of epistemic modality.

Can epistemic luck be captured by modal conditions such as safety from error? This paper answers ‘no’. First, an old problem is cast in a new light: it is argued that the trivial satisfaction associated with necessary truths and accidentally robust propositions is a symptom of a more general disease. Namely, epistemic luck but not safety from error is hyperintensional. Second, it is argued that as a consequence the standard solution to deal with this worry, namely the invocation (...) of content variation, fails. Third, it is considered whether the condition can serve some restricted theoretical role; the hypothesis is rejected. Finally, it is tentatively suggested that epistemic luck’s hyperintensionality derives from its being an explanatory notion, and an analogy is drawn with failures of probabilstic conceptions of explanation in the philosophy of science. (shrink)

Some have argued for a division of epistemic labor in which mathematicians supply truths and philosophers supply their necessity. We argue that this is wrong: mathematics is committed to its own necessity. Counterfactuals play a starring role.

Predicate approaches to modality have been a topic of increased interest in recent intensional logic. Halbach and Welch :71–100, 2009) have proposed a new formal technique to reduce the necessity predicate to an operator, demonstrating that predicate and operator methods are ultimately compatible. This article concerns the question of whether Halbach and Welch’s approach can provide a uniform formal treatment for intensionality. I show that the monotonicity constraint in Halbach and Welch’s proof for necessity fails for almost all (...) possible-worlds theories of knowledge. The nonmonotonicity results demonstrate that the most obvious way of emulating Halbach and Welch’s rapprochement of the predicate and operator fails in the epistemic setting. (shrink)

The once deeply held conviction that all necessary truths are known a priori is now widely, although by no means universally agreed to have been subjected to penetrating, if not devastating criticism. Scott Soames, for example, on behalf of Saul Kripke, and indirectly of Hilary Putnam, argues that in respect of natural kinds, the introduction of basic essentialist assumptions grounded in our pre-theoretical habits of thinking and speaking – for example, that atomic or molecular structure provides the underlying essence of (...) a substance – allows a sentence like "water = H 2 0," in which the identity sign is flanked by rigid designators to express a metaphysically necessary truth. Yet doubts and puzzlement remain over the status of a posteriori necessities, including those relating to an individual's origin. This paper considers some prominent criticisms that have been made of the Kripke–Putnam approach by A. J. Ayer and Frank Ebersole among others and reveals in what respects they are valid, where they are misplaced, and, perhaps more importantly, why the most valuable aspect of this approach can be seen to reflect aspects of our scientific procedures that do indeed point towards an application for a distinction that roughly mirrors that between epistemic and metaphysical possibility, yet one that is grounded instead in the nature of our actual practices. (shrink)

How does science create knowledge? Epistemic cultures, shaped by affinity, necessity, and historical coincidence, determine how we know what we know. In this book, Karin Knorr Cetina compares two of the most important and intriguing epistemic cultures of our day, those in high energy physics and molecular biology. Her work highlights the diversity of these cultures of knowing and, in its depiction of their differences--in the meaning of the empirical, the enactment of object relations, and the fashioning (...) of social relations--challenges the accepted view of a unified science. By many accounts, contemporary Western societies are becoming "knowledge societies"--which run on expert processes and expert systems epitomized by science and structured into all areas of social life. By looking at epistemic cultures in two sample cases, this book addresses pressing questions about how such expert systems and processes work, what principles inform their cognitive and procedural orientations, and whether their organization, structures, and operations can be extended to other forms of social order. The first ethnographic study to systematically compare two different scientific laboratory cultures, this book sharpens our focus on epistemic cultures as the basis of the knowledge society. (shrink)

How does science create knowledge? Epistemic cultures, shaped by affinity, necessity, and historical coincidence, determine how we know what we know. In this book, Karin Knorr Cetina compares two of the most important and intriguing epistemic cultures of our day, those in high energy physics and molecular biology. The first ethnographic study to systematically compare two different scientific laboratory cultures, this book sharpens our focus on epistemic cultures as the basis of the knowledge society.

In lieu of an abstract, here is a brief excerpt of the content:95. HUME AND NONLOGI CAL NECESSITY Flew substantially agrees with our main themes in Causal Powers, though he thinks our discussion should begin closer to the work of Hume himself. What to reply? Needless to say, we find no fault in his agreement with us and are happy for his support. The answer to the second part of his response is far more complicated and requires a bit (...) of background from Causal Powers. While contemporary Humeans differ in important details, they share certain commitments which constitute what we call the Humean tradition. This tradition and contemporary refinements of it are the targets of our criticisms and provide the crucial foil for presenting our own positive theory of natural necessity. Two important strands of the tradition, as we characterized it, are the In-principle (No-contradiction) argument and the argument against the possibility of a priori knowledge of matters of fact. (i) Since nature may change its course, 'C and not E' is not self-inconsistent. To the Humean the phrase "change in the course of nature" seems intuitively clear; to us it seems utterly opaque and itself in great need of analysis. We show that there are two possible interpretations of the phrase, one of which is selfinconsistent while the other, though coherent, does not establish the Humean conclusion that there is no necessary connection between matters of fact, (ii) The Humean assumes that 'p is contingent' and 'p is a posteriori. ' and 'p is necessary' and 'p is a priori, ' are materially equivalent, and then argues easily that since all causal propositions are a posteriori none of them can be a priori and so necessary. We offer numerous arguments to break up the assumed equivalencies and thus defeat the conclusion 96. of the Humean argument. We show that while all scientific propositions are indeed known a posteriori it does not follow that there are no justifiable propositions about natural kinds. Philosophers in other traditions have made a similar point in showing that "metaphysical necessity" does not entail "epistemic necessity." Indeed, in contrast to many contemporary Humeans, we are complete fallibilists and even reject the notion that there is a self-contained given which is incorrigible. In portraying various strands of "the Humean tradition" in Causal Powers, we were, of course, imputing these views to Hume himself. How could it be otherwise? In referring to the Humean tradition instead of to Hume we meant only to indicate (as do contemporary Humeans) that we were concerned only with what we take to be still very much alive in Hume's work. Hence it is puzzling to read Flew' s remark that we relate our own contributions to Hume "only most distantly." That we and contemporary Humeans are always correct in what we ascribe to Hume and in what we take to be still philosophically alive in his work may be open to question, but since Flew does not challenge any specific ascription there is no alleged misinterpretation to defend ourselves against. Flew suggests that we should show Hume to be wrong at the outset — convict him, so to speak, on the grounds of the inconsistencies in his own texts. He refers to the famous definition of 'cause' in the Inquiry, where Hume gives a factual rendition of 'cause' and then innocently equates it with a counterfactual counterpart. C. J. Ducasse, for many years an ardent critic of Hume texts, made this point nicely in 1924 in his splendid book Causation and the Types of Necessity. After quoting Hume's definition in the Inquiry Ducasse remarked: This statement, incidentally, is immediately followed by: "Or in other words where, if the first object had not been, the second never had 97. existed." But this, far from being only a different way of saying precisely the same thing, is on the contrary a precise way of saying a very different thing. For Hume very definitely maintains elsewhere that there is never any "if-ness" objectively observable at all, but only a "that-ness" constantly repeated in experience. So that only the first statement is consistent with his empiricism, and even in that first statement the words "are followed" should in strictness be replaced by... (shrink)

This chapter contains sections titled: Modality Semantics Form Epistemic Matters Recapitulation Mathematical Notions.

Sosa's work on epistemic circularity has significance beyond his own brand of virtue epistemology, with its characteristic distinction between animal and reflective knowledge. On the contrary, it demonstrates the necessity of embracing foundationalism and externalism in epistemology, while at the same time answering various charges (some perennial) against epistemology in general. This paper distinguishes six kinds of epistemic circularity that are discussed in Sosa's work: two virtuous, two vicious, and two benign. This framework is used to reconstruct (...) Sosa's responses to various problems involving charges of epistemic circularity. In particular, we look at Sosa's response to e Problem of the Criterion. (shrink)

This paper develops an account of the meaning of `ought', and the distinction between weak necessity modals (`ought', `should') and strong necessity modals (`must', `have to'). I argue that there is nothing specially ``strong'' about strong necessity modals per se: uses of `Must p' predicate the (deontic/epistemic/etc.) necessity of the prejacent p of the actual world (evaluation world). The apparent ``weakness'' of weak necessity modals derives from their bracketing whether the necessity of the (...) prejacent is verified in the actual world. `Ought p' can be accepted without needing to settle that the relevant considerations (norms, expectations, etc.) that actually apply verify the necessity of p. I call the basic account a modal-past approach to the weak/strong necessity modal distinction (for reasons that become evident). Several ways of implementing the approach in the formal semantics/pragmatics are critically examined. The account systematizes a wide range of linguistic phenomena: it generalizes across flavors of modality; it elucidates a special role that weak necessity modals play in discourse and planning; it captures contrasting logical, expressive, and illocutionary properties of weak and strong necessity modals; and it sheds light on how a notion of `ought' is often expressed in other languages. These phenomena have resisted systematic explanation. In closing I briefly consider how linguistic inquiry into differences among necessity modals may improve theorizing on broader philosophical issues. (shrink)

Epistemic two-dimensional semantics is a theory in the philosophy of language that provides an account of meaning which is sensitive to the distinction between necessity and apriority. While this theory is usually presented in an informal manner, I take some steps in formalizing it in this paper. To do so, I define a semantics for a propositional modal logic with operators for the modalities of necessity, actuality, and apriority that captures the relevant ideas of epistemic two-dimensional (...) semantics. I also describe some properties of the logic that are interesting from a philosophical perspective, and apply it to the so-called nesting problem. (shrink)

Gila Sher approaches knowledge from the perspective of the basic human epistemic situation—the situation of limited yet resourceful beings, living in a complex world and aspiring to know it in its full complexity. What principles should guide them? Two fundamental principles of knowledge are epistemic friction and freedom. Knowledge must be substantially constrained by the world (friction), but without active participation of the knower in accessing the world (freedom) theoretical knowledge is impossible. This requires a grounding of all (...) knowledge, empirical and abstract, in both mind and world, but the fall of traditional foundationalism has led many to doubt the viability of this ‘classical’ project. Sher challenges this skepticism, charting a new foundational methodology, foundational holism, that differs from others in being holistic, world-oriented, and universal (i.e., applicable to all fields of knowledge). Using this methodology, Epistemic Friction develops an integrated theory of knowledge, truth, and logic. This includes (i) a dynamic model of knowledge, incorporating some of Quine’s revolutionary ideas while rejecting his narrow empiricism, (ii) a substantivist, non-traditional correspondence theory of truth, and (iii) an outline of a joint grounding of logic in mind and world. The model of knowledge subjects all disciplines to demanding norms of both veridicality and conceptualization. The correspondence theory is robust and universal yet not simplistic or naive, admitting diverse forms of correspondence. Logic’s grounding in the world brings it in line with other disciplines while preserving, and explaining, its strong formality, necessity, generality, and normativity. (shrink)

Is knowledge the epistemic norm of action and assertion? Gettier and justified-false-belief cases have been raised as counterexamples to the necessity direction of that claim. Most knowledge normers reply by distinguishing permissibility from excusability. An important objection to this move, however, is that it requires a still lacking view of epistemic excuses sufficiently general to cover all the cases, correctly relating the supposed excuse to the subject's cognitive life, and not collapsing into an account of the fundamental (...) normative standard (see Gerken 2017). In this paper, I rely on independent work in epistemology and cognitive science to suggest a novel account of epistemic excuses in terms of epistemic feelings. In contrast to other existing accounts, this account is immune from the above objection and can thus be used to rescue the knowledge norm. (shrink)

The present work is motivated by two questions. (1) What should an intuitionistic epistemic logic look like? (2) How should one interpret the knowledge operator in a Kripke-model for it? In what follows we outline an answer to (2) and give a model-theoretic definition of the operator K. This will shed some light also on (1), since it turns out that K, defined as we do, fulfills the properties of a necessity operator for a normal modal logic. The (...) interest of our construction also lies in a better insight into the intuitionistic solution to Fitch's paradox, which is discussed in the third section. In particular we examine, in the light of our definition, De Vidi and Solomon's proposal of formulating the verification thesis as Φ → ¬¬KΦ. We show, as our main result, that this definition excapes the paradox, though it is validated only under restrictive conditions on the models. (shrink)

Theorists with otherwise radically different commitments agree that epistemic modals mark the necessity or possibility of a prejacent proposition relative to a body of evidence or knowledge. However, there is vast disagreement about the semantics of epistemic modals, which stems in part from the fact that statements of epistemic possibility or necessity make no explicit reference to a speaker or group, an audience, or an evidence set. This volume introduces new philosophical papers that mark a (...) significant contribution to the debate about epistemic modals. (shrink)

This article raises problems both for the view that safe belief is necessary for knowledge and for the view that it is sufficient. Focusing on ‘meta‐epistemic beliefs,’ or beliefs about the epistemic status of one's own beliefs, it is shown that the necessity claim has counterintuitive implications and that the sufficiency claim implies a contradiction. It is then shown that meta‐epistemic beliefs raise similar problems for a wide range of accounts of knowledge, and hence that they (...) provide a powerful test for theories of knowledge. (shrink)

A prevailing thought is that generics have a covert modal operator at logical form. I claim that if this is right, the covert generic modality is a weak necessity modal. In this paper, I pr...

In _The Morality of Defensive Force_, Quong defends a powerful account of the grounds and conditions under which an agent may justifiably inflict serious harm on another person. In this paper, I examine Quong's account of the necessity constraint on permissible harming—the RESCUE account. I argue that RESCUE does not succeed. Section 2 describes RESCUE. Section 3 raises some worries about Quong's conceptual construal of the right to be rescued and its attendant duties. Section 4 argues that RESCUE does (...) not deliver the verdicts that Quong wants. In those sections, I assume that the attacker is culpable for the threat he poses. Section 5 considers cases where the attacker, though responsible for the wrongful threat he poses and therefore liable to defensive force, has an epistemic justification for acting as he does and thus is not morally culpable. In his discussion of necessity, Quong does not explicitly deal with such cases. I suggest that RESCUE does not operate in the same way when attackers are mistaken as when they are morally culpable. (shrink)

The received view says that possibility is the dual of necessity: a proposition is (metaphysically, logically, epistemically etc.) possible iff it is not the case that its negation is (metaphysically, logically, epistemically etc., respectively) necessary. This reading is usually taken for granted by modal logicians and indeed seems plausible when dealing with logical or metaphysical possibility. But what about epistemic possibility? We argue that the dual definition of epistemic possibility in terms of epistemic necessity generates (...) tension when reasoning about non-idealized agents and is a problem of concern for most hyperintensional epistemic logics that alleviate the problem of logical omniscience. The tension is particularly evident when knowledge is taken as a primitive to define other epistemic concepts, such as justification and belief, as done in the knowledge-first tradition. We propose a non-dual interpretation of epistemic possibility, employing a hyperintensionality filter similar to the one that makes the corresponding epistemic necessity operator hyperintensional. We employ the proposed semantics to model Stalnaker's belief as epistemic possibility of knowledge and provide a sound and complete axiomatization for a hyperintensional version of his bimodal logic of knowledge and belief. (shrink)

We intend at this article to show some reasons to think the laws of nature as metaphysically necessary: to distinguish the metaphysical modality from the epistemical modality, and to have an absolute modality to face the relative physical and logical modalities. Lately, we indicate what does it mean to talk about metaphysically necessary laws, distinguishing two kinds of metaphysical modalities, and we account for the question about if the laws of nature are metaphysically necessary. The conclusion we get is that (...) the laws, whichever they are, are metaphysically necessary. (shrink)

In this article, I show that (i) from what I call a “Kripkean” account of the relations between conceivability and metaphysical necessities, (ii) an apparently plausible principle relating conceivability and epistemic modality, and (iii) the duality of epistemic modalities, one can show the utterly anti-Kripkean result that every metaphysical necessity is an epistemic necessity. My aim is to present and diagnose the problem and evaluate the costs of some possible Kripkean reactions. In particular, I will (...) evaluate the consequences and theoretical costs of rejecting the main ingredients of the argument, namely that we cannot genuinely conceive the negations of metaphysical necessities, that there is no postulated relation between conceivability and epistemic possibility (actually, between unconceivability and epistemic impossibility), and that epistemic possibility and necessity are not dualities. (shrink)

This paper develops an update semantics for weak necessity modals like ‘ought’ and ‘should’. I start with the basic approach to the weak/strong necessity modal distinction developed in Silk 2018: Strong necessity modals are given their familiar semantics of necessity, predicating the necessity of the prejacent of the actual world (evaluation world). The apparent “weakness” of weak necessity modals derives from their bracketing the assumption that the relevant worlds in which the prejacent is necessary (...) (deontically, epistemically, etc.) need be candidates for actuality. ‘Should φ’ can be accepted without needing to settle that the relevant considerations (norms, preferences, expectations, etc.) that actually apply, given the facts, verify the necessity of φ. I formalize these ideas within an Update with Centering framework. The meaning of ‘Should φ’ is explained, fundamentally, in terms of how its use updates attention toward possibilities in which φ is necessary. The semantics is also extended to deontic conditionals. The proposed analyses capture various contrasting logical properties and discourse properties of ‘should’ and ‘must’ — e.g., in sensitivities to standing contextual assumptions, entailingness, and force — and provide an improved treatment of largely neglected data concerning information-sensitivity. (shrink)

So far, T×W frames have been employed to provide a semantics for a language of tense logic that includes a modal operator that expresses historical necessity. The operator is defined in terms of quantification over possible courses of events that satisfy a certain constraint, namely, that of being alike up to a given point. However, a modal operator can as well be defined without placing that constraint. This paper outlines a T×W logic where an operator of the latter kind (...) is used to express the epistemic property of definiteness. Section 1 provides the theoretical background. Sections 2 and 3 set out the semantics. Sections 4 and 5 show, drawing on established results, that there is a sound and complete axiomatization of the logic outlined. (shrink)

I intend to argue that the counterexamples inspired by the Frankfurt-type cases against the necessity of an epistemic safety condition for knowledge are not plausible. The epistemic safety condition for knowledge is a modal condition recently supported by Sosa (2007) and Pritchard (2015), among others, and can be formulated as follows: (SC) If S knows that p on basis B, then S’s true belief that p could not have easily been false on basis B. I will try (...) to argue that the safety condition, expressed in (SC), is still necessary for knowledge and that, therefore, epistemic safety is not threatened by Frankfurt-type cases. In particular, I want to show that Kelp’s counterexamples are ineffective against (SC). (shrink)

I argue that considerations about computational complexity show that all finite agents need characteristics like those that have been called epistemic virtues. The necessity of these virtues follows in part from the nonexistence of shortcuts, or efficient ways of finding shortcuts, to cognitively expensive routines. It follows that agents must possess the capacities – metavirtues –of developing in advance the cognitive virtues they will need when time and memory are at a premium.

In the first chapter I have introduced Carnapian intensional logic against the background of Frege's and Quine's puzzles. The main body of the dissertation consists of two parts. In the first part I discussed Carnapian modal logic and arithmetic with descriptions. In the second chapter, I have described three Carnapian theories, CCL, CFL, and CNL. All three theories have three things in common. First, they are formulated in languages containing description terms. Second, they contain a system of modal logic. Third, (...) they do not contain the unrestricted classical substitution principle, but they do contain the classical substitution principle restricted to non-modal formulas and the Carnapian substitution principle, which says that two terms can be substituted salva veritate if they are necessarily coreferential. There are two major differences between the three theories. First, CCL and CFL allow universal instantiation with description terms, whereas CNL does not. Moreover, the quantificational theory of the CCL is classical, whereas the quantificational theory of CFL is a free logic. Another difference is that CCL and CFL contain different description principles. Most importantly, the description principle of CCL ensures that even improper descriptions have a denotation, whereas the description principle of CFL does not guarantee this. CNL does not have a description principle. In the third chapter, I have studied collapse arguments for CCL, CFL, and CNL. A collapse argument is an argument for the following statement: if p is true, then it is necessarily true. A crucial role in the proofs of these collapse results was played by so-called self-predication principles, which say that under certain conditions the predicate that expresses the descriptive condition can be combined by the description term formed out of that predicate with the result being a true sentence. In this chapter I have discussed a collapse argument for the extension of CCL with a self-predication principle, I have given a collapse argument for a similarly extended CFL, and most importantly, I have given a collapse argument for the extension of CNL with a self- predication principle. Finally, I have argued that the relevant self-predication principles are unsound under a Carnapian interpretation. In the fourth chapter, I have studied the extension of Peano Arithmetic with a Carnapian modal logic C, which is a dummy letter standing for either CCL or CFL. One can prove that the principle of the necessity of identity is a theorem of CPA. This implies that one gets a collapse result for CPA. The standard principle of weak induction was crucial for the proof. One can also prove that, if one assumes a particular self-predication principle, and if one assumes the principle of strong induction or, equivalently, the least-number principle, then one gets a partial collapse of de re modal truths in de dicto modal truths. I have argued that, if the box operator is interpreted as a metaphysical necessity operator, then Platonists would not be inimical to the collapse result. But if CPA is extended with a physical theory, then there is a threat that physical truths become physical necessiti es. It was shown that, under a Carnapian interpretation, the standard principle of weak induction is unsound, and that it can be replaced by a Carnapian principle of weak induction that is sound. The problem of logical and mathematical omniscience prevents ordinary Carnapian intensional logic from being taken seriously as a logic adequate for describing the principles of demonstrability. Yet many of the proof-theoretic results of the first part carry over to the part on Carnapian epistemic arithmetic with descriptions, since proof-theoretic results are independent of the informal reading of the operators. In the fifth chapter, I looked at extensions of arithmetic with a modal logic in which the box operator is interpreted as a demonstrability operator. A first extension in that sense is Shapiro s Epistemic Arithmetic. Shapiro himself offered the problem of mathematical omniscience as a reason why it is difficult to find a model theory for EA. Horsten attempted to provide a model theory via the detour of Modal-Epistemic Arithmetic. The attention of the reader was drawn to an incoherence in the model theory of. Two alternative solutions were presented and, after a short discussion of the problem of de re demonstrability one of those alternatives was chosen. The discussion of the problem of de re demonstrability made it clear that it would be interesting to study the epistemic properties of notation systems. Horsten himself provided a framework for this, viz. Carnapian Epistemic Arithmetic, and he started a systematic study of the epistemic properties of notation systems within that framework. However, he did not provide non-trivial but adequate models. To make a start with solving the problem of finding good models for CEA, I introduced Carnapian Modal-Epistemic Arithmetic In constructing CMEA I incorporated the lesson about the principle of weak induction learnt in the fourth chapter. In the sixth chapter, I gave a critical assessment of an argument concerning the limits of de re demonstrability about the natural numbers. The conclusion of the Description Argument is that it is undemonstrable that there is a natural number that has a certain property but of which it is undemonstrable that it has that property. A crucial step in the Description Argument involved a self-predication principle. Making good use of one of the results obtained in the third chapter, I proved a collapse result for the background theory against which the Description Argument was formulated. I concluded that either the either the Description Argument is sound but its conclusion is trivial, o r the Description Argument is unsound, or it is a cheapshot. As an appendix I included an article co-authored by prof. dr. Leon Horsten and me. The topic of the article is indirectly related to some other topics investigated in my dissertation. Also, it backs up one of the addition al theses I might be asked to publicly defend during my doctoral exam. T he topic of the appendix is the set of the so-called paradoxes of strict implication. Jonathan Lowe has argued that a particular variation on C.I. Lewis notion of strict implication avoids the paradoxes of strict implication. Pace Lowe, it is argued that Lowe s notion of implication does not achieve this aim. Moreover, a general argument is offered to the effect that no other variation on Lewis notion of constantly strict implication describes the logical behaviour of natural language conditional s in a satisfactory way. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Epistemic Leaks and Epistemic Meltdowns: A Response to William Morris on Scepticism with Regard to Reason Mikael M. Karlsson I. In an excellent paper which appeared in the April, 1989 issue of this journal,2 William Morris attemptsto demonstrate thatthe arguments which make up Hume's notorious chapter, "Of scepticism with regard to reason, are, in the first place, coherent—both internally and with the overall strategy of the Treatise—and, (...) in the second place, successful. Morris' paper is an exercise in the noble art of what I style constructive exegesis, an enterprise to which many readers of Hume Studies, and myself as much as any, are committed. It is a guiding principle ofthis art that we donotunderstandaphilosophical textuntil we can interpret it in such a way as to render it both coherent and correct. From this point ofview, coherence and correctness are not as independent of one another as they may seem to be to others who are differently committed. Some texts, such as Hume's chapter, "Ofscepticism with regard to reason," are notoriously resistant to constructive exegesis, despite the formidable bag of tricks which scholars and interpreters have developed; so resistant, that in gloomier moments we may be brought to wonder about our interpretative enterprise itself. Constructive exegesis is indeed a strange, and peculiarly optimistic, enterprise. Someday, I imagine, in a leisurely moment, I will think more reflectively about the principles ofour art. But not now.6 As a fellow practitioner of constructive exegesis, I am in full sympathy with what Morris tries to do in his paper; and I think that he does contribute substantially to our understanding of what Hume is up to in the chapter, "Ofscepticism with regard to reason." The third section of Morris' paper is, in my judgement, particularly successful in showing how Hume's chapter fits into the larger framework of the Treatise: Hume is, we see, attacking both what Morris labels "intellectualist rationalism" and its counterpart, which we may call 'unmitigated scepticism', although the chapter's two main arguments go primarily to the former. I also think that Morris gives very helpful, Volume XVI Number 2 121 MIKAEL M. KARLSSON and to my mind accurate, accounts of these two arguments, which I dub, respectively, the epistemic leak argument, and the epistemic meltdown argument. However, I have personally never found either of these arguments remotely convincing; and I still do not, despite Morris' clarification and defense. In what follows, I shall indicate some ofthe reasons for my dissatisfaction.?. Theepistemicleakargumentpurportsto"prove"(in Hume's sense)that reason or demonstration cannot support knowledge. Morris rightlyreminds us that whatHume meansby knowledge is perfect assurance or conviction: Knowledge is, in short, subjective certainty. This has caused confusion, for this is not what we usually mean nowadays by knowledge; nor was it what people, philosophers included, generally meant prior to Descartes. In Hume itis the product ofthe attempttoresolve all epistemic statesintomental eventsorwhat he calls "perceptions." In any case, we must—as Morris rightly explains—be clear that the epistemic leak argument is aimed at showing that demonstration cannot supportperfect conviction. Inoutline, the argumentissimple: Itworks, asMorrismakes clear, by shifting attention away from the subject-matter or "objects" of demonstration, that is, relations of ideas, to the exercise of demonstrative reason by human agents. The necessity of relations of ideas may suggest to us that we can be certain about them. Against this, one may point out that people do err in the conclusions arrived at by demonstration; this presumably shows that our (rational) understandingis fallible. And once we recognize this, our confidence in any conclusion produced by exercising this facultyislessened—thus do we move from knowledge, or subjective certainty, toprobability: belief, or imperfect conviction. Arguments ofthis general type (we can call them, using Descartes' famous figure, Totten-apple arguments ) were around long before Hume, although they were more commonly directed against the senses than against reason. We find them in antiquity—in Plato and Sextus Empiricus, for instance —and in Descartes, in parallel passages in the Discourse on Method, the First Meditation and the Principles of Philosophy, wherein one can discern a version directed precisely against reason and demonstration.12 To find out what, if anything, Hume has... (shrink)

Over the last three decades, joint action has received various definitions, which for all their differences share many features. However, they cannot fit some perplexing cases of weak joint action, such as demonstrations, where agents rely on distinct epistemic sources, and as a result, have no first-hand knowledge about each other. I argue that one major reason why the definition of such collective actions is akin to the classical ones is that it crucially relies on the concept of common (...) knowledge. To this end, I first argue for the necessity of common knowledge for joint action in general due to the increased reliability of success it entails. I then defend the relevance of common knowledge against several criticisms, point at an adequate weakening, and discuss alternative approaches. Although structurally weaker, the common knowledge has a richer content in weak joint actions. As a result, even if the links between individuals are seriously stretched, much is still shared among them. Weak joint actions still require considerable cognitive abilities indeed. (shrink)

I argue that considerations about computational complexity show that all finite agents need characteristics like those that have been called epistemic virtues. The necessity of these virtues follows in part from the nonexistence of shortcuts, or efficient ways of finding shortcuts, to cognitively expensive routines. It follows that agents must possess the capacities – metavirtues –of developing in advance the cognitive virtues they will need when time and memory are at a premium.

Epistemic modal verbs and adverbs of necessity are claimed to be positive polarity items. We study their behavior by examining modal spread, a phenomenon that appears redundant or even anomalous, since it involves two apparent modal operators being interpreted as a single modality. We propose an analysis in which the modal adverb is an argument of the MUST modal, providing a meta-evaluation \ which ranks the Ideal, stereotypical worlds in the modal base as better possibilities than the Non-Ideal (...) worlds in it. MUST and possibility modals differ in that the latter have an empty \, a default that can be negotiated. Languages vary in the malleability of this parameter. Positive polarity is derived as a conflict between the ranking imposed by \—which requires that the Ideal worlds be better possibilities than Non-Ideal worlds—and the effect of higher negation which renders the Ideal set non-homogenous. Applying the ordering over such a non-homogeneous set would express preference towards both p and \ worlds thus rendering the sentence uninformative. Negative polarity MUST and possibility modals, on the other hand, contain an empty \, application of higher negation therefore poses no problem. This account is the first to connect modal spread to positive polarity of necessity modals, and captures the properties of both in a unified analysis. (shrink)

In Philosophy and the Mirror of Nature, Richard Rorty presents powerful arguments against traditional epistemology, conceived as a quest both for empirical grounds that provide certainty and for necessary truths that provide a conceptual framework within which to couch empirical findings. Rorty finds traditional epistemology in general, and specifically any appeal to representation that might ground knowledge, to be an unmitigated failure. In this paper, I show that Rorty at least considered but ultimately rejected the possibility of a type of (...) epistemically relevant, foundational representation with a normative status. Drawing on the work of Tyler Burge, I argue that Rorty was too quick in dismissing the important, epistemically foundational role of perceptual representation. A new and improved picture of foundational epistemology emerges. Throughout the paper, I aim to shed light on the fundamental disconnect between Rorty’s and Burge’s approaches to epistemology, and to philosophical investigation more generally. (shrink)