In this article, I argue that access internalism should replace preservationism, which has been called “a received view” in the epistemology of memory, as the standard position about memorial justification. My strategy for doing so is two-pronged. First, I argue that the considerations which motivate preservationism also support access internalism. Preservationism is mainly motivated by its ability to answer the explanatory challenges posed by the problem of stored belief and the problem of forgotten evidence. However, as I will demonstrate, access (...) internalism also has the resources to provide plausible solutions to those problems. Second, I argue that preservationism faces a couple of problems which access internalism avoids. Doing so, I present a new scenario which, on the one hand, functions as a counterexample to preservationism, and, on the other hand, provides intuitive support for access internalism. Moreover, I also demonstrate how preservationism, in light of recent research in cognitive psychology, is vulnerable to skepticism about memorial justification, whereas access internalism remains unthreatened. (shrink)

Past public announcement operators have been defined in Hoshi and Yap :259–281, 2009) and Yap, to describe an agent’s knowledge before an announcement occurs. These operators rely on branching-time structures that do not mirror the traditional, relativization-based semantics of public announcement logic, and favor a historical reading of past announcements. In this paper, we introduce reverse public announcement operators that are interpreted on expanded models. Our model expansion adds accessibility links from an epistemic model \ to a filtrated submodel of (...) the canonical model for \. Here \ is the minimal normal modal logic together with \ axioms for the universal operator U. This yields a highly general pre-announcement version of \ that makes our operators potentially useful for studying non-standard interpretations of rescinded announcements in PAL. Indeed, we find that our reverse announcement operators cannot be represented by product update, and that they have an intimate connection with the knowledge forgetting of Zhang and Zhou :1525–1537, 2009). We show that the logic resulting from adding reverse announcements to PAL is sound and complete. (shrink)

Theoria , the international Swedish philosophy journal, was founded in 1935. Its contributors in the first 75 years include the major Swedish philosophers from this period and in addition a long list of international philosophers, including A. J. Ayer, C. D. Broad, Ernst Cassirer, Hector Neri Castañeda, Arthur C. Danto, Donald Davidson, Nelson Goodman, R. M. Hare, Carl G. Hempel, Jaakko Hintikka, Saul Kripke, Henry E. Kyburg, Keith Lehrer, Isaac Levi, David Lewis, Gerald MacCallum, Richard Montague, Otto Neurath, Arthur N. (...) Prior, W. V. Quine, Nicholas Rescher, Ernest Sosa, Robert C. Stalnaker, P. F. Strawson, Patrick Suppes, Johan van Benthem, Georg Henrik von Wright and many others. Hempel's confirmation paradoxes, Ross's deontic paradox, Montague's universal grammar and Lindström's theorem are among the contributions to philosophy that were first published in Theoria. (shrink)

In 1960, E. P. Wigner, a joint winner of the 1963 Nobel Prize for Physics, published a paper titled On the Unreasonable Effectiveness of Mathematics in the Natural Sciences [61]. This paper can be construed as an examination and affirmation of Galileo's tenet that “The book of nature is written in the language of mathematics”. To this effect, Wigner presented a large number of examples that demonstrate the effectiveness of mathematics in accurately describing physical phenomena. Wigner viewed these examples as (...) illustrations of what he called the empirical law of epistemology, which asserts that the mathematical formulation of the laws of nature is both appropriate and accurate, and that mathematics is actually the correct language for formulating the laws of nature. At the same time, Wigner pointed out that the reasons for the success of mathematics in the natural sciences are not completely understood; in fact, he went as far as asserting that “… the enormous usefulness of mathematics in the natural sciences is something bordering on the mysterious and there is no rational explanation for it.”. (shrink)

The question of whether knowledge is definable in terms of belief, which has played an important role in epistemology for the last 50 years, is studied here in the framework of epistemic and doxastic logics. Three notions of definability are considered: explicit definability, implicit definability, and reducibility, where explicit definability is equivalent to the combination of implicit definability and reducibility. It is shown that if knowledge satisfies any set of axioms contained in S5, then it cannot be explicitly defined in (...) terms of belief. S5 knowledge can be implicitly defined by belief, but not reduced to it. On the other hand, S4.4 knowledge and weaker notions of knowledge cannot be implicitly defined by belief, but can be reduced to it by defining knowledge as true belief. It is also shown that S5 knowledge cannot be reduced to belief and justification, provided that there are no axioms that involve both belief and justification. (shrink)

Crosslinguistically, the same modal words can be used to express a wide range of interpretations. This crosslinguistic trend supports a Kratzerian analysis, where each modal has a core lexical entry and where the difference between an epistemic and a root interpretation is contextually determined. A long-standing problem for such a unified account is the equally robust crosslinguistic correlation between a modal’s interpretation and its syntactic behavior: epistemics scope high (in particular higher than tense and aspect) and roots low, a fact (...) which has led to proposals that hardwire different syntactic positions for epistemics and roots (cf. Cinque’s hierarchy). This paper argues that the range of interpretations a modal receives is even more restricted: a modal must be keyed to certain time-individual pairs, but not others. I show that this can be captured straightforwardly by minimally modifying the Kratzerian account: modals are relative to an event—rather than a world—of evaluation, which readily provides a time (the event’s running time) and (an) individual(s) (the event’s participants). I propose that this event relativity of modals can in turn explain the correlation between type of interpretation and syntactic position, without stipulation of an interpretation-specific height for modals. (shrink)

This paper discusses the interaction of aspect and modality, and focuses on the puzzling implicative effect that arises when perfective aspect appears on certain modals: perfective somehow seems to force the proposition expressed by the complement of the modal to hold in the actual world, and not merely in some possible world. I show that this puzzling behavior, originally discussed in Bhatt (1999, Covert modality in non-finite contexts) for the ability modal, extends to all modal auxiliaries with a circumstantial modal (...) base (i.e., root modals ), while epistemic interpretations of the same modals are immune to the effect. I propose that implicative readings are contingent on the relative position of the modal w.r.t. aspect: when aspect scopes over the modal (as I argue is the case for root modals), it forces an actual event, thereby yielding an implicative reading. When a modal element scopes over aspect, no actual event is forced. This happens (i) with epistemics, which structurally appear above tense and aspect; (ii) with imperfective on a root modal: imperfective brings in an additional layer of modality, itself responsible for removing the necessity for an actual event. This proposal enables us to solve the puzzle while maintaining a standardized semantics for aspects and modals. (shrink)

The paper develops an interface between syntax-based logical models of awareness and dynamic epistemic logic. The framework is shown to be able to accommodate a variety of notions of awareness and knowledge, as well as their dynamics. This, it is argued, offers a natural formal environment for the analysis of epistemic phenomena typical of multi-agent information exchange, such as how agents become aware of relevant details, how they perform inferences and how they share their information within a group. Technically, the (...) logics presented are all simple refinements of the logic of public announcements. (shrink)

Though my ultimate concern is with issues in epistemology and metaphysics, let me phrase the central question I will pursue in terms evocative of philosophy of religion: What are the implications of our logic-in particular, of Cantor and G6del-for the possibility of omniscience?

Epistemic iteration principles are principles according to which some or another epistemic operator automatically iterates---e.g., if it is known that P, then it is known that P, or there is evidence that P, then there is evidence that there is evidence that P. This article provides a survey of various arguments for and against epistemic iteration principles, with a focus on arguments relevant to a wide range of such principles.

The Hooded Man Paradox of Eubulides concerns the apparent failure of the substitutivity of identicals in epistemic (and other intentional) contexts. This paper formulates a number of different versions of the paradox and shows how these may be solved using semantics for quantified epistemic logic. In particular, two semantics are given which invalidate substitution, even when rigid designators are involved.

Dynamic epistemic logic describes the possible information-changing actions available to individual agents, and their knowledge pre-and post conditions. For example, public announcement logic describes actions in the form of public, truthful announcements. However, little research so far has considered describing and analysing rational choice between such actions, i.e., predicting what rational self-interested agents actually will or should do. Since the outcome of information exchange ultimately depends on the actions chosen by all the agents in the system, and assuming that agents (...) have preferences over such outcomes, this is a game theoretic scenario. This is, in our opinion, an interesting general research direction, combining logic and game theory in the study of rational information exchange. In this article we take some first steps in this direction: we consider the case where available actions are public announcements, and where each agent has a (typically epistemic) goal formula that she would like to become true. What will each agent announce? The truth of the goal formula also depends on the announcements made by other agents. We analyse such public announcement games. (shrink)

A true lie is a lie that becomes true when announced. In a logic of announcements, where the announcing agent is not modelled, a true lie is a formula that becomes true when announced. We investigate true lies and other types of interaction between announced formulas, their preconditions and their postconditions, in the setting of Gerbrandy’s logic of believed announcements, wherein agents may have or obtain incorrect beliefs. Our results are on the satisfiability and validity of instantiations of these semantically (...) defined categories, on iterated announcements, including arbitrarily often iterated announcements, and on syntactic characterization. We close with results for iterated announcements in the logic of knowledge, and for lying as private announcements to different agents. Detailed examples illustrate our lying concepts. (shrink)

Contextology is the science of the dynamics of the conversational context. Contextology formulates laws governing how the shared information states of interlocutors evolve in response to assertion. More precisely, the contextologist attempts to construct a function which, when provided with just a conversation’s pre-update context and the content of an assertion, delivers that conversation’s post-update context. Most contextologists have assumed that the function governing the evolution of the context is simple: the post-update context is just the pre-update context intersected with (...) the content of the assertion. We argue that this assumption is wrong: not only is it false, it is also incoherent given standard contextological assumptions. Moreover, it is impossible in principle to revise it to correctly describe the dynamics of context. We conclude that there can be no science of Contextology. The laws governing the evolution of the context in response to assertion must make essential reference to the private information states of interlocutors. (shrink)

In this paper we deal with a classical question of western philosophy: Is it possible to know that there are things which do not exist? We begin with a brief analysis of some fragments of Parmenides, and later we study whether these arguments are valid using three kinds of epistemic logic: a classical style epistemic logic, where axiom holds, a free epistemic logic, where this axiom does not hold, and finally, we study Lenzen's proposal of using two kinds of quantifiers: (...) possibilistic and realistic quantifiers. We conclude that the last last one is the closest to our intuition and a good way to deal with this kind of problem. (shrink)

The paper is in two parts. In Part I, a semantics for embedded and query uses of interrogatives is put forward, couched within a situation semantics framework. Unlike many previous analyses,questions are not reductively analysed in terms of their answers. This enables us to provide a notion of ananswer that resolves a question which varies across contexts relative to parameters such as goals and inferential capabilities. In Part II of the paper, extensive motivation is provided for an ontology that distinguishes (...) propositions, questions, and facts, while at the same time the semantics provided captures an important commonality between questions and propositions: factsprove propositions andresolve questions. This commonality is exploited to provide an explanation for why predicates such as know carry presuppositions such as factivity and for a novel account of the behaviour of adverbially modified predicates with interrogative, declarative and fact-nominal arguments. (shrink)

This paper discusses the possibility of modelling inductive inference (Gold 1967) in dynamic epistemic logic (see e.g. van Ditmarsch et al. 2007). The general purpose is to propose a semantic basis for designing a modal logic for learning in the limit. First, we analyze a variety of epistemological notions involved in identification in the limit and match it with traditional epistemic and doxastic logic approaches. Then, we provide a comparison of learning by erasing (Lange et al. 1996) and iterated epistemic (...) update (Baltag and Moss 2004) as analyzed in dynamic epistemic logic. We show that finite identification can be modelled in dynamic epistemic logic, and that the elimination process of learning by erasing can be seen as iterated belief-revision modelled in dynamic doxastic logic. Finally, we propose viewing hypothesis spaces as temporal frames and discuss possible advantages of that perspective. (shrink)

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)

This paper consists of two main parts and a coda. In the first part I present the ''binding theory'' of presupposition projection, which is the framework that I adopt in this paper (Section 1.1). I outline the main problems that arise in the interplay between presuppositions and anaphors on the one hand and attitude reports on the other (Section 1.2), and discuss Heim''s theory of presuppositions in attitude contexts (Section 1.3).In the second part of the paper I present my own (...) proposal. To begin with, I define an extension of DRT in which attitude reports can be represented (Sections 2.1–2.2). I then argue that the verb believe triggers a certain presupposition and that, given the binding theory, this presupposition determines the projection behaviour of the verb (Section 2.3). This analysis yields predictions which are incomplete in the sense that they do not fully account for speakers'' intuitions about presuppositions and anaphors in belief contexts. In Section 2.4 I suggest that this is as it should be because we may assume on independent grounds that there is a class of plausibility inferences which complement the predictions of the presupposition theory. Finally, the analysis is extended to the verb want (Section 2.5). (shrink)

In the basic modal language and in the basic modal language with the added universal modality, first-order definability of all formulas over the class of all frames is shown. Also, it is shown that the problems of modal definability of first-order sentences over the class of all frames in the languages and are both PSPACE-complete.

M. B. Hintikka and J. Hintikka claimed that their reconstruction of the ‘Sherlock Holmes sense of deduction’ can “serve as an explication for the link between intelligence and memory”. The claim is vindicated, first for the single-agent case, where the reconstruction captures strategies for accessing the content of a distributed and associative memory; then, for the multi-agent case, where the reconstruction captures strategies for accessing knowledge distributed in a community. Moreover, the reconstruction of the ‘Sherlock Holmes sense of deduction’ allows (...) to conceptualize those strategies as belonging to a continuum of behavioral strategies. (shrink)

I explain what exactly constrains presupposition projection in compound sentences and argue that the presuppositions that do not project are conditionalized, giving rise to inferable conditional presuppositions. I combine elements of and which, together with an additional, independently motivated assumption, make it possible to construct an analysis that makes correct predictions. The core of my proposal is as follows: When a speaker felicitously utters a compound sentence whose constituent clauses require presuppositions, the hearer will infer that the speaker presupposes those (...) propositions, unless the sentence contains some element that makes the hearer realize that, if the speaker actually presupposed them, she would be either uninformative or inconsistent in her beliefs. In these cases, the propositions that would have been presupposed, had the clauses been uttered in isolation, will not be presupposed, i.e. the clausal presuppositions will not project. (shrink)

Thomason (1979/2010)'s argument against competence psychologism in semantics envisages a representation of a subject's competence as follows: he understands his own language in the sense that he can identify the semantic content of each of its sentences, which requires that the relation between expression and content be recursive. Then if the scientist constructs a theory that is meant to represent the body of the subject's beliefs, construed as assent to the content of the pertinent sentences, and that theory satisfies certain (...) 'natural assumptions', then it implies that the subject is inconsistent if the beliefs include arithmetic. I challenge the result by insisting that the motivation for Thomason's principle (ii), via Moore's Paradox, leads to a more complex representation, in which stating the facts and expressing one's beliefs are treated differently. Certain logical connections among expressions of assent, and between expression and statement, are a matter of consequence on pain of pragmatic incoherence, not consequence on pain of classical logical inconsistency. But while this salvages the possibility that a modification of the above sort of representation could be adequate, Thomason's devastating conclusion returns if the scientist identifies himself as the subject of that representation, even when paying heed to the requirement of pragmatic coherence of the sort highlighted by Moore's Paradox. (shrink)

It is widely held within contemporary metaethics that there is a lack of linguistic support for evaluative expressivism. On the contrary, it seems that the predictions that expressivists make about evaluative discourse are not borne out. An instance of this is the so-called problem of missing Moorean infelicity. Expressivists maintain that evaluative statements express non-cognitive states of mind in a similar manner to how ordinary descriptive language expresses beliefs. Conjoining an ordinary assertion that p with the denial of being in (...) the corresponding belief state famously gives rise to Moorean infelicity:?? It’s raining but I don’t believe that it’s raining. If expressivists are right, then conjoining evaluative statements with the denial of being in the relevant non-cognitive state of mind should give rise to similar infelicity. However, as several theorists have pointed out, this does not seem to be the case. Statements like the following are not infelicitous: Murder is wrong but I don’t disapprove of it. In this paper, I argue that evaluative statements express the kind of states that are attributed by ‘find’-constructions in English and that these states are non-cognitive in nature. This addresses the problem of missing Moorean infelicity and, more generally, goes to show that there are linguistic facts which support expressivism about evaluative discourse. (shrink)

In this paper, I focus on the Armchair Access Problem for E=K as presented by Nicholas Silins (2005), and I argue, contra Silins, that it does not represent a real threat to E=K. More precisely, I put forward two lines of response, both of which put pressure on the main assumption of the argument, namely, the Armchair Access thesis. The first line of response focuses on its scope, while the second line of response focuses on its nature. The second line (...) of response is the most interesting one, for it represents the framework within which I develop a novel account of second-order knowledge, one that involves evaluation of counterfactual conditionals and the employment of our imaginative capacities, i.e., an imagination-based account of second-order knowledge. The two lines of response are shown to be jointly compatible and mutually supportive. I then conclude that the Armchair Access Problem is not a challenge for E=K, yet it relies on the ambiguity of the notion of armchair knowledge underpinning the Armchair Access thesis. (shrink)

The object of this essay is to demonstrate a logical connection between beliefs and values. It is argued that such a connection can be established only if one keeps in mind the question: What is minimally required in order that it makes sense to speak of beliefs and values at all? Thus, the concept of minimal rationality is indispensable to the task at hand. A particular example of a logical connection between a belief and a value is examined, which leads (...) to a formal rule (Rule of Minimal Rationality) which expresses in general the logical connection between beliefs and values. This rule is elaborated to include attempted activities as well as activities simpliciter, activities having been discovered as essential to any logical connection between beliefs and values. Finally, some interesting implications and promising applications of the Rule of Minimal Rationality are outlined. (shrink)

The combination of quantifiers with a semantics for epistemic operators in a modal framework is one of the major contributions of Hintikka in intensional logic. Hintikka’s starting point is his diagnosis of the failure of existential generalization and the substitution of identicals in terms of referential multiplicity. In this paper, I introduce Hintikka as a free logician. Indeed, Hintikka’s first-order epistemic logic is grounded on a logic free of ontological presuppositions with respect to singular terms. It is also a logic (...) free of presuppositions of uniqueness of reference. After having focused on the use of quantifiers and singular terms in Hintikka’s epistemic logic, I discuss some consequences from a semantico-logical perspective, but also from a philosophical one. By arguing against the so-called contingent a priori truths defended by Kripke, I conclude with a proposal in favour of Hintikka’s non-rigid interpretation of proper names. (shrink)

In this article, I define and then defend the principle of information closure (pic) against a sceptical objection similar to the one discussed by Dretske in relation to the principle of epistemic closure. If I am successful, given that pic is equivalent to the axiom of distribution and that the latter is one of the conditions that discriminate between normal and non-normal modal logics, a main result of such a defence is that one potentially good reason to look for a (...) formalization of the logic of “ $S$ is informed that $p$ ” among the non-normal modal logics, which reject the axiom, is also removed. This is not to argue that the logic of “ $S$ is informed that $p$ ” should be a normal modal logic, but that it could still be insofar as the objection that it could not be, based on the sceptical objection against pic, has been removed. In other word, I shall argue that the sceptical objection against pic fails, so such an objection provides no ground to abandon the normal modal logic B (also known as KTB) as a formalization of “ $S$ is informed that $p$ ”, which remains plausible insofar as this specific obstacle is concerned. (shrink)

A new semantics is presented for the logic of proofs (LP), [1, 2], based on the intuition that it is a logic of explicit knowledge. This semantics is used to give new proofs of several basic results concerning LP. In particular, the realization of S4 into LP is established in a way that carefully examines and explicates the role of the + operator. Finally connections are made with the conventional approach, via soundness and completeness results.

is used to give a formalization of Artemov’s knowledge based reasoning approach to game theory, (KBR), [ 4 , 5 ]. Epistemic states of players are represented explicitly and reasoned about formally. We give a detailed analysis of the Centipede game using both proof theoretic and semantic machinery. This helps make the case that PDL + E can be a useful basis for the logical investigation of game theory.

A propositional logic of explicit proofs, LP, was introduced in [S. Artemov, Explicit provability and constructive semantics, The Bulletin for Symbolic Logic 7 1–36], completing a project begun long ago by Gödel, [K. Gödel, Vortrag bei Zilsel, translated as Lecture at Zilsel’s in: S. Feferman , Kurt Gödel Collected Works III, 1938, pp. 62–113]. In fact, LP can be looked at in a more general way, as a logic of explicit evidence, and there have been several papers along these lines. (...) A major result about LP is the Realization Theorem, that says any theorem of S4 can be converted into a theorem of LP by some replacement of necessitation symbols with explicit proof terms. Thus the necessitation operator of S4 can be seen as a kind of implicit existential quantifier: there exists a proof term such that…. In this paper, quantification over evidence is introduced into LP, and it is shown that the connection between S4 necessitation and the existential quantifier becomes an explicit one. The extension of LP with quantifiers is called QLP. A semantics and an axiom system for QLP are given, soundness and completeness are established, and several results are proved relating QLP to LP and to S4. (shrink)

We introduce a methodology whereby an arbitrary logic system L can be enriched with temporal features to create a new system T(L). The new system is constructed by combining L with a pure propositional temporal logic T (such as linear temporal logic with Since and Until) in a special way. We refer to this method as adding a temporal dimension to L or just temporalising L. We show that the logic system T(L) preserves several properties of the original temporal logic (...) like soundness, completeness, decidability, conservativeness and separation over linear flows of time. We then focus on the temporalisation of first-order logic, and a comparison is make with other first-order approaches to the handling of time. (shrink)

O slogan "Conhecimento gera dogmatismo" causa-nos imediata perplexidade. O dogmatismo é trivialmente tomado como uma postura irracional de manutenção de crenças. Saul Kripke, contra esta intuitiva perspectiva, ofereceu um argumento que supostamente prova que se você sabe que uma proposição P é verdadeira, então você está autorizado a ser dogmático quanto a se P. Neste ensaio, temos os seguintes objetivos. Em primeiro lugar, vamos criticar uma recente objeção ao argumento pró-dogmatismo de Kripke feita por Rodrigo Borges, segundo a qual, uma (...) suposição sobre meta-conhecimento deve ser assumida por Kripke a fim de que seu argumento seja defensável. Em segundo lugar, vamos propor uma outra crítica ao argumento de Kripke, segundo a qual uma de suas premissas assume uma perigosa dose de voluntarismo doxástico, o que compromete irremediavelmente o seu argumento. Concluiremos que embora o argumento de Kripke possa ser defendido de certas críticas, a sua conclusão paradoxical é injustificada. (shrink)

La lógica de la conciencia es una extensión de la lógica epistémica que solventa el problema de la omnisciencia lógica incorporando un operador de conciencia para separar el conocimiento explícito del implícito. Este informe recopila los principales textos tanto de los orígenes de esta lógica, así como de sus desarrollos en las últimas tres décadas. En concreto analiza los enfoques desde la lógica epistémica dinámica, desde su combinación con otras lógicas y los enfoques de teoría de juegos.

The 1985 paper by Carlos Alchourrón (1931–1996), Peter Gärdenfors, and David Makinson (AGM), "On the Logic of Theory Change: Partial Meet Contraction and Revision Functions" was the starting-point of a large and rapidly growing literature that employs formal models in the investigation of changes in belief states and databases. In this review, the first twentyfive years of this development are summarized. The topics covered include equivalent characterizations of AGM operations, extended representations of the belief states, change operators not included in (...) the original framework, iterated change, applications of the model, its connections with other formal frameworks, computatibility of AGM operations, and criticism of the model. (shrink)

The 1985 paper by Carlos Alchourrón, Peter Gärdenfors, and David Makinson, “On the Logic of Theory Change: Partial Meet Contraction and Revision Functions” was the starting-point of a large and rapidly growing literature that employs formal models in the investigation of changes in belief states and databases. In this review, the first twenty-five years of this development are summarized. The topics covered include equivalent characterizations of AGM operations, extended representations of the belief states, change operators not included in the original (...) framework, iterated change, applications of the model, its connections with other formal frameworks, computatibility of AGM operations, and criticism of the model. (shrink)

with this paper, we intend to clarify some of the central notions that are commonly used in contemporary developments of Epistemic Logic, which lack a proper theoretical foundation. We want to follow the steps of some prominent epistemologists and epistemic logicians, who advocate for a correlation between their respective fields of study. We will proceed with a first small step that will consist in adapting one contemporary version of Epistemic Internalism to the framework of Awareness Logic, such that the key (...) concepts in this logic can be sustained by an epistemological view, which, in turn, can work as a theoretical foundation for Awareness Logic. (shrink)

In recent years, some authors have shown a renewed interest in interpretivist theories of folk psychological ascription [Hutto 2013. “Fictionalism About Folk Psychology.” The Monist 96 (4): 582–604.; Mölder 2010. Mind Ascribed: An Elaboration and Defence of Interpretivism. Amsterdam: John Benjamins; Sanchez-Curry 2020. “Interpretivism and Norms.” Philosophical Studies 177 (4): 905– 930.; Mölder 2021. “Interpretivism Without Judgement- Dependence.” Philosophia 49 (2): 611–615.; Slors 2015. "Interpretivism and the Meaning of Mental State Ascriptions." Studia Philosophica Estonica, 10 (2): 18–27.]. Part of the (...) virtue of interpretivism lies in its ability to provide an answer to elminativist arguments without falling into the assumptions and problems of intentional realism. However, some recent developments in semantic expressivism applied to normative expressions could help to build an alternative theory to interpretivism that would enjoy the same virtues. The aim of this paper is to present and defend an expressivist approach to the status of folk psychological ascriptions. According to this view, mental states ascriptions are evaluative and non-descriptive statement that express or reflect certain normative standards or values of the attributor. After presenting the view and contrasting it with interpretivist positions, with which expressivism shares important motivations and claims, I present two arguments to favor the expressivist analysis. In line with the first argument, expressivism can account for fundamental aspects of disagreements regarding mental attributions while the second highlights the capacity of the view to explain the widespread justificatory and exculpatory uses of mental states ascriptions. (shrink)

The hallmark of the deductive systems known as ‘conceptivist’ or ‘containment’ logics is that for all theorems of the form , all atomic formulae appearing in also appear in . Significantly, as a consequence, the principle of Addition fails. While often billed as a formalisation of Kantian analytic judgements, once semantics were discovered for these systems, the approach was largely discounted as merely the imposition of a syntactic filter on unrelated systems. In this paper, we examine a number of prima (...) facie unrelated deductive contexts in which Addition fails and attempt to harmonise them by developing a computational interpretation of conceptivist logics. (shrink)

Dispositionalist accounts of belief define beliefs in terms of specific sets of dispositions. In this article, I provide a blind-spot argument against these accounts. The core idea of the argument is that beliefs having the form [p and it is not manifestly believed that p] cannot be manifestly believed. This means that one cannot manifest such beliefs in one’s assertions, conscious thoughts, actions, behaviours, or any other type of activity. However, if beliefs are sets of dispositions, they must be manifestable (...) in some way. Therefore, according to my argument, beliefs are not sets of dispositions. The argument is defended against some possible objections. (shrink)

In this article, we study logics of unknown truths and false beliefs under neighborhood semantics. We compare the relative expressivity of the two logics. It turns out that they are incomparable over various classes of neighborhood models, and the combination of the two logics are equally expressive as standard modal logic over any class of neighborhood models. We propose morphisms for each logic, which can help us explore the frame definability problem, show a general soundness and completeness result, and generalize (...) some results in the literature. We axiomatize the two logics over various classes of neighborhood frames. Most importantly, by adopting the intersection semantics and the subset semantics in the literature, we extend the results to the case of public announcements, which gives us the desired reduction axioms and has good applications related to Moore sentences, successful formulas and self-refuting formulas. Also, we can say something about the comparative merits of the intersection semantics and the subset semantics. (shrink)

The Dunning–Kruger effect focuses our attention on the notion of invisibility of ignorance, i.e., the ignorance of ignorance. Such a phenomenon is not only important for everyday life, but also, above all, for some philosophical disciplines, such as epistemology of sciences. When someone tries to understand formally the phenomenon of ignorance of ignorance, they usually end up with a nested epistemic operator highly resistant to proper regimentation. In this paper, we argue that to understand adequately the ignorance of ignorance phenomenon (...) we have to understand satisfactorily the concept of disbelief and, as we call it, the concept of “radical ignorance”. We propose also prerequisites that a notion of radical ignorance useful for the philosophy of science ought to fulfill, and we sketch a possible formalization of this notion. Finally, we propose some comments on the problem of propagation of ignorance proposed by Fine. (shrink)

Contingency and accident are two important notions in philosophy and philosophical logic. Their meanings are so close that they are mixed up sometimes, in both daily life and academic research. This indicates that it is necessary to study them in a unified framework. However, there has been no logical research on them together. In this paper, we propose a language of a bimodal logic with these two concepts, investigate its model-theoretical properties such as expressivity and frame definability. We axiomatize this (...) logic over various classes of frames, whose completeness proofs are shown with the help of a crucial schema. The interactions between contingency and accident can sharpen our understanding of both notions. Then we extend the logic to a dynamic case: public announcements. By finding the required reduction axioms, we obtain a complete axiomatization, which gives us a good application to Moore sentences. (shrink)