A growing number of epistemologists have endorsed the Ignorance Norm for Inquiry. Roughly, this norm says that one should not inquire into a question unless one is ignorant of its answer. I argue that, in addition to ignorance, proper inquiry requires a certain kind of knowledge. Roughly, one should not inquire into a question unless one knows it has a true answer. I call this the Knowledge Norm for Inquiry. Proper inquiry walks a fine line, holding knowledge that there is (...) an answer in the left hand and ignorance of the answer in the right. (shrink)

Knowledge is good, ignorance is bad. So it seems, anyway. But in this dissertation, I argue that some ignorance is epistemically valuable. Sometimes, we should suspend judgment even though by believing we would achieve knowledge. In this apology for ignorance (ignorance, that is, of a certain kind), I defend the following four theses: 1) Sometimes, we should continue inquiry in ignorance, even though we are in a position to know the answer, in order to achieve more than mere knowledge (e.g. (...) understanding) while minimizing the effects of confirmation bias. 2) It’s false that we should believe every proposition such that we are guaranteed to be right about it (and even such that we are guaranteed to know it) if we believe it. 3) Being in a position to know is the norm of assertion: importantly, this does not require belief or (thereby) knowledge, and so proper assertion can survive speaker-ignorance. 4) It can be permissible and conversationally useful to tell audiences things that it is logically impossible for them to come to know: Proper assertion can survive (necessary) audience-side ignorance. Cumulatively, this project suggests that, properly understood, ignorance has an important role to play in the good epistemic life. (shrink)

The Free Choice effect—whereby \\) seems to entail both \ and \—has traditionally been characterized as a phenomenon affecting the deontic modal ‘may’. This paper presents an extension of the semantic account of free choice defended by Fusco to the agentive modal ‘can’, the ‘can’ which, intuitively, describes an agent’s powers. On this account, free choice is a nonspecific de re phenomenon that—unlike typical cases—affects disjunction. I begin by sketching a model of inexact ability, which grounds a modal approach to (...) agency in a Williamson -style margin of error. A classical propositional semantics combined with this framework can reflect the intuitions highlighted by Kenny ’s dartboard cases, as well as the counterexamples to simple conditional views recently discussed by Mandelkern et al.. In Section 3, I turn to an independently motivated actual-world-sensitive account of disjunction, and show how it extends free choice inferences into an object language for propositional modal logic. (shrink)

How to say no less, no more about conditional than what is needed? From a logical analysis of necessary and sufficient conditions (Section 1), we argue that a stronger account of conditional can be obtained in two steps: firstly, by reminding its historical roots inside modal logic and set-theory (Section 2); secondly, by revising the meaning of logical values, thereby getting rid of the paradoxes of material implication whilst showing the bivalent roots of conditional as a speech-act based on affirmations (...) and rejections (Section 3). Finally, the two main inference rules for conditional, viz. Modus Ponens and Modus Tollens, are reassessed through a broader definition of logical consequence that encompasses both a normal relation of truth propagation and a weaker relation of falsity non-propagation from premises to conclusion (Section 3). (shrink)

In the present version of these lecture notes only a number of typos and a few glaring mistakes have been corrected. Thanks to Paul Dekker for his help in this respect. No attempt has been been made to update the original text or to incorporate new insights and approaches. For a more recent overview, see our ‘Questions’ in the Handbook of Logic and Language (edited by Johan van Benthem and Alice ter Meulen, Elsevier, 1997).

Whether mathematical truths are syntactical (as Rudolf Carnap claimed) or empirical (as Mill actually never claimed, though Carnap claimed that he did) might seem merely an academic topic. However, it becomes a practical concern as soon as we consider the role of questions. For if we inquire as to the truth of a mathematical statement, this question must be (in a certain respect) meaningless for Carnap, as its truth or falsity is certain in advance due to its purely syntactical (or (...) formal-semantical) nature. In contrast, for Mill such a question is as valid as any other. These differing views have their consequences for contemporary erotetic logic. (shrink)

The purpose of this paper is to give a semantical analysis of why-questions. Why-questions will be construed as requests for knowledge. Special attention will be paid to considering what the conditions for conclusive answerhood are in the case of why-questions. Since explanations can often be thought of as answers to why-questions, we also discuss some topics in the theory of explanation.

A long line of epistemologists including Sosa (2021), Feldman (2002), and Chisholm (1977) have argued that, at least for a certain class of questions that we take up, we should (or should aim to) close inquiry iff by closing inquiry we would meet a unique epistemic standard. I argue that no epistemic norm of this general form is true: there is not a single epistemic standard that demarcates the boundary between inquiries we are forbidden and obligated to close. In short, (...) such norms are false because they are insensitive to the potentially ambitious epistemic goals that agents may permissibly bring to bear on an inquiry. Focusing particularly on knowledge-oriented versions of the norm, I argue that ignorance has a positive role to play in epistemic life by licensing prolonged inquiry into questions that we especially care about. (shrink)

In many natural languages, there are clear syntactic and/or intonational differences between declarative sentences, which are primarily used to provide information, and interrogative sentences, which are primarily used to request information. Most logical frameworks restrict their attention to the former. Those that are concerned with both usually assume a logical language that makes a clear syntactic distinction between declaratives and interrogatives, and usually assign different types of semantic values to these two types of sentences. A different approach has been taken (...) in recent work on inquisitive semantics. This approach does not take the basic syntactic distinction between declaratives and interrogatives as its starting point, but rather a new notion of meaning that captures both informative and inquisitive content in an integrated way. The standard way to treat the logical connectives in this approach is to associate them with the basic algebraic operations on these new types of meanings. For instance, conjunction and disjunction are treated as meet and join operators, just as in classical logic. This gives rise to a hybrid system, where sentences can be both informative and inquisitive at the same time, and there is no clearcut division between declaratives and interrogatives. It may seem that these two general approaches in the existing literature are quite incompatible. The main aim of this paper is to show that this is not the case. We develop an inquisitive semantics for a logical language that has a clearcut division between declaratives and interrogatives. We show that this language coincides in expressive power with the hybrid language that is standardly assumed in inquisitive semantics, we establish a sound and complete axiomatization for the associated logic, and we consider a natural enrichment of the system with presuppositional interrogatives. (shrink)

Ordinary Language Philosophy has largely fallen out of favour, and with it the belief in the primary importance of analyses of ordinary language for philosophical purposes. Still, in their various endeavours, philosophers not only from analytic but also from other backgrounds refer to the use and meaning of terms of interest in ordinary parlance. In doing so, they most commonly appeal to their own linguistic intuitions. Often, the appeal to individual intuitions is supplemented by reference to dictionaries. In recent times, (...) Internet search engine queries for expressions of interest have become quite popular. Apparently, philosophers attempt to surpass the limits of their own linguistic intuitions by appealing to experts or to factual uses of language. I argue that this attempt is commendable but that its execution is wanting. Instead of appealing to dictionaries or Internet queries, philosophers should employ computer-based linguistic corpora in order to confirm or falsify hypotheses about the factual use of language. This approach also has some advantages over methods employed by experimental philosophers. If the importance of ordinary language is stressed, the use of linguistic corpora is hardly avoidable. (shrink)

This paper studies the distribution of ‘list readings’ in questions like who does everyone like? vs. who likes everyone?. More generally, it focuses on the interaction between wh-words and quantified NPs. It is argued that, contrary to widespread belief, the pattern of available readings of constituent questions can be explained as a consequence of Weak Crossover, a well-known property of grammar. In particular, list readings are claimed to be a special case of ‘functional readings’, rather than arising from quantifying into (...) questions. Functional readings are argued to be encoded in the syntax as doubly indexed traces, which straightforwardly leads to a Crossover account of the absence of list readings in who likes everyone?. Empirical and theoretical consequences of this idea for the syntax and semantics of questions are considered. (shrink)

In this paper we provide an interpretation of Aristotle's rule for the universal quantifier in Topics Θ 157a34–37 and 160b1–6 in terms of Paul Lorenzen's dialogical logic. This is meant as a contribution to the rehabilitation of the role of dialectic within the Organon. After a review of earlier views of Aristotle on quantification, we argue that this rule is related to the dictum de omni in Prior Analytics A 24b28–29. This would be an indication of the dictum’s origin in (...) the context of dialectical games. One consequence of our approach is a novel explanation of the doctrine of the existential import of the quantifiers in dialectical terms. After a brief survey of Lorenzen's dialogical logic, we offer a set of rules for dialectical games based on previous work by Castelnérac and Marion, to which we add here the rule for the universal quantifier, as interpreted in terms of its counterpart in dialogical logic. We then give textual evidence of the use of that rule in Plato's dialogues, thus showing that Aris... (shrink)

Hong Oak Yun is a person who is over three inches tall. And now you know who Hong Oak Yun is. For if someone were to ask you ‘Who is Hong Oak Yun?’, you could answer that Hong Oak Yun is a person who is over three inches tall, and you would know what you were saying. So you know an answer to the question ‘Who is Hong Oak Yun?’, and that is sufficient for knowing who Hong Oak Yun is. (...) Getting to know who a person is may be easier than you think. (shrink)

Der Begriff der Globalisierung wird in unterschiedlichen Kontexten in jeweils unterschiedlicher Bedeutung benutzt; in ihm kommt es zu einer Verwischung von Tatsachen und Fiktion – von Existentem und Nichtexistentem. Der Globalisierungsbegriff bezieht sich etwa auf staatsübergreifende wirtschaftliche, politische und kulturelle Prozesse. Eine philosophische bzw. konzeptuelle Begründung der Globalisierung gibt es nicht. Westliche philosophische Metanarrative werden lokal interpretiert; eine globale Interpretation von Metanarrativen gibt es nicht. Etymologisch bedeutet ‘Verstehen’: zwischen den Unterschieden stehen, etwa zwischen Tatsachen und Fiktion. Die Logik des Sachwissens (...) ist eine Logik des Stands zwischen Hoffnung und Realität – zwischen Nichtexistentem und Existentem. Die Logik des Sachwissens ist eine generelle Theorie des Verstehens. Als eine wahrhaft allgemeine Theorie ist die Logik des Sachwissens weltweit grenzüberschreitend. Demnach bildet die Logik des Sachwissens die Grundlage für eine Philosophie der Globalisierung. (shrink)

Why do we ask questions? Because we want tohave some information. But why this particular kind ofinformation? Because only information of this particularkind is helpful to resolve the decision problemthat the agent faces. In this paper I argue thatquestions are asked because their answers help toresolve the questioner's decision problem, and that thisassumption helps us to interpret interrogativesentences. Interrogative sentences are claimed to have asemantically underspecified meaning and thisunderspecification is resolved by means of the decisionproblem.

This paper is truly a joint effort and it could not have been written without the contribution of both authors. Garson, though, deserves credit (or blame) for first seeing the need for two kinds of quantifier scope, and also for devising essentials of the positive theory.

This paper presents a simple decidable logic of functional dependence LFD, based on an extension of classical propositional logic with dependence atoms plus dependence quantifiers treated as modalities, within the setting of generalized assignment semantics for first order logic. The expressive strength, complete proof calculus and meta-properties of LFD are explored. Various language extensions are presented as well, up to undecidable modal-style logics for independence and dynamic logics of changing dependence models. Finally, more concrete settings for dependence are discussed: continuous (...) dependence in topological models, linear dependence in vector spaces, and temporal dependence in dynamical systems and games. (shrink)

The Interrogative Model of Inquiry and Dynamic Epistemic Logics are two central paradigms in formal epistemology. This paper is motivated by the observation of a significant complementarity between them: on the one hand, the IMI provides a framework for investigating inquiry represented as an idealized game between an Inquirer and Nature, along with an account of the interaction between questions and inferences in information-seeking processes, but is lacking a formulation in the multi-agent case; on the other hand, DELs model various (...) operations of information change in multi-agent systems, but the field is lacking a proper integration of question and inference dynamics, along with an application to the investigation of inquiry processes. The goal of this paper is to integrate the two paradigms in such a way as to combine their respective insights. To this end, we develop a formal system called DEL $$_\mathrm{IMI }$$ IMI which aims to represent the interaction between question and inference dynamics in inquiry—as described by the IMI—in a multi-agent setting, and this in such a way as to enable an investigation of inquiry games with multi-agent dimensions. The DEL $$_\mathrm{IMI }$$ IMI system is designed to represent the possible moves of such inquiry games through three types of epistemic actions: agents addressing questions to Nature, agents addressing questions to other agents, agents drawing logical inferences. We then show how the resulting framework can be used to formally define multi-agent inquiry games. We conclude by evaluating the interest of the DEL $$_\mathrm{IMI }$$ IMI system for the IMI and DELs paradigms. (shrink)

We consider question-answer dialogues between participants who may disagree with each other. The main problems are: (a) How different speech-acts affect the information in the dialogue; and (b) How to represent what was said in a dialogue, so that we can summarize it even when it involves disagreements (i.e., inconsistencies).We use a fully-typed many-sorted language L with a possible-worlds semantics. L contains nominals representing short answers. The speech-acts are uniformly represented in a dialogue language DL by focus structures, consisting of (...) a mood operator, a topic component and a focus component. Each stage of the dialogue is associated with a set of information functions (g-functions), which are partial functions taking a topic component (representing a question raised) to a set of propositions determined by the corresponding focus component (to the set of answers given to it). (shrink)

Turingin testi, interrogatiivimalli ja tekoäly.

Scientific knowledge systems function as effective and specialized apparatus for formulating, analyzing and solving scientific problems. In science, problems become internal parts of the knowledge systems; thus they acquire new forms and properties in comparison with common-sense problems. Definite theoretical structures connected with problems and questions appear in the theory. Among them are erotetic expressions and languages, calculi and algebras of problems. On the basis of the structure-nominative reconstruction of a theory, the unified treatment of these structures is given. Methods (...) of the theory of named sets are used in the logical analysis of problems and their systems. As a consequence a new formalized model of the problem part of theory is constructed. (shrink)

The aims of this paper are to provide a detailed taxonomy of noncanonical uses of interrogative sentences, i.e. when they are used not to ask a question but to convey some information, or to ask a question albeit not that expressed by the interrogative sentence exploited in the act, to identify properties of circumstances where an interrogative sentence is being used in this way, and to propose some maxims that govern the rational use of questions. Four main categories of such (...) cases are presented, and a few further subclasses are differentiated. I show how these types are interrelated, and what logical features differentiate them. I also propose a hypothesis for when an interrogative sentence is not being used in its primary mode. Studies on circumstances in which questions are used in other ways can shed light on maxims that govern asking and questioning in a rational conversation; therefore, some possible maxims of this kind are proposed. (shrink)

Information exchange can be seen as a dynamic process of raising and resolving issues. The goal of this paper is to provide a logical framework to model and reason about this process. We develop an inquisitive dynamic epistemic logic , which enriches the standard framework of dynamic epistemic logic , incorporating insights from recent work on inquisitive semantics. At a static level, IDEL does not only allow us to model the information available to a set of agents, like standard epistemic (...) logic, but also the issues that the agents entertain. At a dynamic level, IDEL does not only allow us to model the effects of communicative actions that provide new information, like standard DEL, but also the effects of actions that raise new issues. Thus, IDEL provides the fundamental tools needed to analyze information exchange as a dynamic process of raising and resolving issues. (shrink)

With almost a century of historical distance between Heidegger’s retrieval of the question of being and contemporary concern about the Other, we have accrued invaluable experiences for critical leverage about what it is to ask one another questions. I offer a sketch aimed at adapting Tillich’s theological system grounded in existential questioning to today by juxtaposing him with Levinas’ philosophical ethics. Tillich and Levinas provide motive for reflection on the topic of questioning in particular. In the case of Tillich, questions (...) constitute a crucial moment in the dialogue between our contemporary existential situation and religious symbols, or in what he called the ‘method of correlation.’ Furthermore, Tillich locates in the very structure of questioning the germ of our participation in our essential nature despite existential disruption. Beneath his more provocative and prophetic discourse on the absolute desolation and height of the Other, Levinas sees in questions a different kind of possibility. It is not our essential and existential selves, but oneself and the absolutely Other who come together in the question yet retain their infinite difference. Heidegger is the immediate predecessor from whom both Tillich and Levinas inherit a predilection for reflection on questioning. What is at stake is not merely the legacy of Heidegger’s construal of questioning, but, more importantly here, the fundamental sources Tillich and Levinas posit as the origin of our questioning. (shrink)

We propose a novel interpretation of natural-language questions using a modal predicate logic of knowledge. Our approach brings standard model-theoretic and proof-theoretic techniques from modal logic to bear on questions. Using the former, we show that our interpretation preserves Groenendijk and Stokhof's answerhood relation, yet allows an extensional interpretation. Using the latter, we get a sound and complete proof procedure for the logic for free. Our approach is more expressive; for example, it easily treats complex questions with operators that scope (...) over questions. We suggest a semantic criterion that restricts what natural-language questions can express. We integrate and generalize much previous work on the semantics of questions, including Beck and Sharvit's families of subquestions, non-exhaustive questions, and multi-party conversations. (shrink)

It is by way of the call that one is enabled to wake up to responsibility. What is the illocutionary mood of the ‘call’ of conscience, though? Is this transcendental enabler of responsibility an imposing demand or an invitational question? Both Levinas and Heidegger emphasize the impositional character of the call in conscience. The call seems to be the very essence of imperatives. I develop an apology for questioning by way of appeal to crumbs scattered throughout Jewish traditions as well (...) as throughout the works of Levinas and Heidegger. Perhaps we are invited to be rather than told to be. (shrink)