A logic of questions and answers exists within the logic of statements, if we make the following identifications (roughly): "Whether" questions are identified with true exclusive disjunctions, and "which" questions are identified with true existential quantifications. The question-and-answer process is interpreted as an information-matching game. The question mark is not needed except as a device of abbreviation. Complete and partial answers can be distinguished and various relations of relevance, independence, and resolution defined.

This paper argues for the idea that the logic of questions should focus its attention on the analysis of arguments in which questions play the role of conclusions. The relevant concepts of validity are discussed and the concept of the logic of questions of a semantically interpreted formalized language is introduced.

This paper introduces the inquisitive extension of R, denoted as InqR, which is a relevant logic of questions based on the logic R as the background logic of declaratives. A semantics for InqR is developed, and it is shown that this semantics is, in a precisely defined sense, dual to Routley-Meyer semantics for R. Moreover, InqR is axiomatized and completeness of the axiomatic system is established. The philosophical interpretation of the duality between Routley-Meyer semantics and the semantics for InqR (...) is also discussed. (shrink)

Vasso Kindi examines, first, whether Collingwood’s logic of question and answer, which was to replace the symbolic logic of the logical positivists, does indeed bear similarities to Bacon’s and Kant’s use of questions, as Collingwood claims. She argues that Collingwood’s emphasis on questions is more similar to Kant’s concern with presuppositions that make knowledge possible than to Bacon’s interest in pursuing and questioning nature to divulge her secrets. She, then, explains how Collingwood’s emphasis on questions is tied (...) to his view that propositions are not abstract entities with intrinsic meaning in isolation from the network of presuppositions in which they are embedded. Finally, she suggests that the metaphysician’s task, according to Collingwood, is to ‘excavate’ different complexes of questions and answers until the absolute presuppositions which govern them are reached. It is this historical methodology that gives Collingwood’s metaphysics its distinctive character. (shrink)

Questions are triggers for explicit events of ‘issue management’. We give a complete logic in dynamic-epistemic style for events of raising, refining, and resolving an issue, all in the presence of information flow through observation or communication. We explore extensions of the framework to multi-agent scenarios and long-term temporal protocols. We sketch a comparison with some alternative accounts.

Martin Heidegger's 1925–26 lectures on truth and time provided much of the basis for his momentous work, Being and Time. Not published until 1976 as volume 21 of the Complete Works, three months before Heidegger's death, this work is central to Heidegger's overall project of reinterpreting Western thought in terms of time and truth. The text shows the degree to which Aristotle underlies Heidegger's hermeneutical theory of meaning. It also contains Heidegger’s first published critique of Husserl and takes major steps (...) toward establishing the temporal bases of logic and truth. Thomas Sheehan's elegant and insightful translation offers English-speaking readers access to this fundamental text for the first time. (shrink)

Traditional logical theories are concerned with the characterization of valid reasoning. For such logical theories, the main object of investigation is the notion of entailment, a notion that is construed as a relation between two or more declarative statements, dictating when one of them can be legitimately inferred from the others. In the course of the previous century, however, and especially since the 1970s, the scope of logical theories has become much broader. In particular, logic is no longer only concerned (...) with declarative statements, but also with questions. Accordingly, the field is no longer focusing exclusively on the entailment relation that may hold between two or more statements, but also aims to characterize fundamental relations that may hold between questions, or between questions and statements. For instance, when does a statement resolve a given question? When does a statement evoke a certain question? And when does the resolution of one question depend on the resolu .. (shrink)

The aim of this paper is to understand the philosophical role of Collingwood’s proposed logic of question and answer. I shall consider its historical background as a response to Bradley, to the “realists” and to the logical positivists. I shall also consider the similarities and differences between it and modern developments in logics of question and answer and also in anti-realist philosophical logic. In analysing Collingwood’s proposed logic, and its potential for development, I shall attempt a sketch of how (...) it would work out in formal terms. To be sure Collingwood dismissed the symbolism of Russell and Whitehead’s Principia Mathematica as “typographical jargon” and he thought the various artificial logical languages of his time to be “numerous and frightful offspring of propositional logic out of illiteracy”. Nevertheless he did recognise an important role for the logician in articulating his system, namely to identify what it is to be a proposition and what it is to be a question and in doing so to identify what constitutes an “absolute presupposition”. Moreover since Collingwood’s day there have been important developments in logic and semantics, which are expressed through typographical jargon, and yet which are highly relevant to Collingwood’s proposed logic and to its philosophical role. (shrink)

Philosophers and scientists are concerned with the why and the how of things. Questions like the following are so much grist for the philosopher’s and scientist’s mill: How can we be free and yet live in a deterministic universe?, How do neural processes give rise to conscious experience?, Why does conscious experience accompany certain physiological events at all?, How is a three-dimensional perception of depth generated by a pair of two-dimensional retinal images?. Since Belnap and Steel’s pioneering work on (...) the logic of questions, Van Fraassen has managed to apply their approach in constructing an account of the logic of why-questions. Comparatively little, by contrast, has been written on the logic of how-questions despite the apparent centrality of questions such as How is it possible for us to be both free and determined? to philosophical enterprise.1 In what follows I develop a logic for how-questions of various sorts including how-questions of cognitive resolution, how-questions of manner, how-questions of method, of means, and of mechanism. (shrink)

The question, R. M. Hare concedes, “has assumed great importance in the thought of some philosophers, for example Cook Wilson and Collingwood.” A concession, because after a couple of sentences Hare concludes: “we need say no more about questions.” The implication is that in contrast with his two Oxford predecessors the topic has little importance in his philosophy. This isn’t quite so, it will be seen. But it is in line with a tendency among philosophers to relegate the topic, (...) often quite literally, to a footnote. They would be wiser to take questions more seriously; not least because any theory of meaning which connects meaning in some way to the concept of truth—as most do—has to explain how interrogative sentences, which cannot sensibly be said to express what is true or false, can yet have a meaning. Questions also present a challenge to the easy assumption that all thought is either true or false. Even to think of something, it can be argued, is to think that certain descriptions are true of it: to think of a cat is to think of something as having four legs, fur, and so forth. Collingwood’s way of meeting the challenge isn’t immediately apparent. In An Autobiography he does seem to reject the assumption. (shrink)

A collection of interviews with influential theorists working in philosophy of logic. The questions: Why were you initially drawn to the philosophy of logic? What are your main contributions to the philosophy of logic? What is the proper role of philosophy of logic in relation to other disciplines, and to other branches of philosophy? What have been the most significant advances in the philosophy of logic? What are the most important open problems in philosophy of logic, and what are (...) the prospects for progress? Interviews with JC Beall, John Lane Bell, Johan van Benthem, Patricia A. Blanchette, Otávio Bueno, James Cargile, Mark Colyvan, Newton Carneiro Affonso da Costa, Pascal Engel, Susan Haack, Jaakko J. Hintikka, Dale Jacquette, Penelope Maddy, Lawrence S. Moss, Catarina Dutilh Novaes, Ahti-Veikko Pietarinen, Graham Priest, Stephen Read, Nicholas Rescher, Stewart Shapiro, Peter Simons, Timothy Williamson, Jan Woleński. (shrink)

Recently, it has become a custom to treat questions as a game between two subjects. Unfortunately, one rarely goesbeyond the scheme of Questioner-Scientist and Answerer-Nature, althoughthe Interlocutor so conceived displays some undesirable features. This paperargues for the idea that logic of questions can be build as a logic of the gamebetween “knowledge resources” persons or theories, rather than errant Scientist and omniscient Nature. To this end the concept of epistemically-possibleworlds is discussed, which is conceived as analogous to that (...) of possible worldsin modal logic. And, furthermore, the concepts of relation of epistemic alternativeness and of epistemically-alternative worlds are introduced. On thisbasis a version of semantics for propositional, three-valued logic of questionsis offered and semantic proofs of some theses are given. (shrink)

I consider two cognitive phenomena: inquiring and justifying, as complementary processes running in opposite directions. I explain on an example that the former process is driven by questions and the latter is a codification of the results of the first one. Traditionally, proof theory focuses on the latter process, and thus describes the former, at best, as an example of a backward proof search. I argue that this is not the best way to analyze cognitive processes driven by (...) class='Hi'>questions, and that proof-theoretical analysis of questions can bring mutual benefits for both proof theory and erotetic logic. In the second part of my paper (sect. 6.3) I introduce the structural rules of weakening and contraction. Results concerning their admissibility are discussed. I also sketch an erotetic interpretation of the rule of weakening as reducing information noise, and that of contraction as securing information. (shrink)

Questions are triggers for explicit events of 'issue management'. We give a complete logic in dynamic-epistemic style for events of raising, refining, and resolving an issue, all in the presence of information flow through observation or communication. We explore extensions of the framework to multiagent scenarios and long-term temporal protocols. We sketch a comparison with some alternative accounts.

This book is a study in the logic of questions (sometimes called erotetic logic). The central topics in erotetic logic have been the structure of questions and the question-answer relationship. This book doesn't neglect these problems, but much of it is focussed on other issues. The main subject is the logical analysis of certain relations between questions and the contexts of their appearance. And our aim is to elaborate the conceptual apparatus of the inferential approach to the (...) logic of questions. Questions are asked for many reasons and for different purposes. Yet, before a question is asked or posed, a questioner must arrive at it. In many cases arriving at a question resembles coming to a conclusion: there are some premises involved and some inferential thought processes take place. If we agree that a conclusion need not be "conclusive", we may say that sometimes questions can play the role of conclusions. But questions can also perform the role of premises: we often pass from some "initial" question to another question. In other words, there are inferential thought processes - we shall call them erotetic inferences - in which questions play the roles of conclusions or conclusions and premises. The inferential approach to the logic of questions focusses its attention on the analysis of erotetic inferences. This book consists of eight chapters. (shrink)

Quentin Skinner has enduringly insisted that a past text cannot be ‘understood’ without the reader knowing something about its historical and linguistic context. But since the 1970s he has been attacked on this central point of all his work by authors maintaining that the text itself is the fundamental guide to the author’s intention, and that a separate study of the context cannot tell the historian anything that the text itself could not. Mark Bevir has spent much of the last (...) 20 years repeating a similar counter-argument. Although ‘study the linguistic context’ might be a useful heuristic maxim, Bevir says, it does not express a necessary or sufficient condition for understanding. But Skinner is right, and one of the figures he has consistently identified as a formative inspiration, R. G. Collingwood, has already (in his work of the 1930s) shown why. What Collingwood calls his ‘logic of question and answer’ explains why the historian cannot answer his characteristic ‘intention’ question about past texts without knowing the context of problems to which authors think they are offering solutions. The study of context is neither ‘prior’ (as Bevir incorrectly supposes) nor ‘separate’ (as Skinner inaccurately says), but it is, as Skinner maintains, nevertheless impossible to grasp an author’s intention without it. This ‘logic of question and answer’ also explains why, in history, dismissing the study of context is in fact a pre-judgement of evidence yet unseen. (shrink)

In the course of proving a tenability result about the probabilities of conditionals, van Fraassen (1976) introduced a semantics for conditionals based on ω-sequences of worlds, which amounts to a particularly simple special case of ordering semantics for conditionals. On that semantics, ‘If p, then q’ is true at an ω-sequence just in case q is true at the first tail of the sequence where p is true (if such a tail exists). This approach has become increasingly popular in recent (...) years. However, its logic has never been explored. We axiomatize the logic of ω-sequence semantics, showing that it is the result of adding two new axioms to Stalnaker’s logic C2: one, Flattening, which is prima facie attractive, and, and a second, Sequentiality, which is complex and difficult to assess, but, we argue, likely invalid. But we also show that when sequence semantics is generalized from ω-sequences to arbitrary (transfinite) ordinal sequences, the result is a more attractive logic that adds only Flattening to C2. We also explore the logics of a few other interesting restrictions of ordinal sequence semantics. Finally, we address the question of whether sequence semantics is motivated by probabilistic considerations, answering, pace van Fraassen, in the negative. (shrink)

The pair (A, Δ ), where A is a physical quantity (an observable) and Δ a subset of the reals, may be called an 'experimental question'. The set Q of experimental questions is, in classical mechanics, a Boolean algebra, and in quantum mechanics an orthomodular lattice (and also a transitive partial Boolean algebra). The question is raised: can we specify a priori what algebraic structure Q must have in any theory whatsoever? Several proposals suggesting that Q must be a (...) lattice are discussed, and rejected in favor of the weak claim that Q must be a Boolean atlas. (shrink)

The paper explores two ways in which the logic of questions might aid in the understanding of explanations. First, the "logic" of question-answer sequences imposes constraints on what answers are acceptable for an inquirer. Secondly, there are field- specific type-requirements built into questions. There is always more to a question than meets the potential answerer's ear. It is argued that, since there are nonepistemic presuppositions of why-questions, there are no interesting necessary and sufficient conditions for all explanations. (...) Explanations are a family of concepts tied together by the thin thread of the logic of question-answer sequences. (shrink)

History and Philosophy of Logic, Volume 32, Issue 2, Page 193-196, May 2011.

This work is central to Heidegger's overall project of reinterpreting Western thought in terms of time and truth.

Philosophers at least since Kant, with Larry Laudan being a recent example, have suggested that scientific inquiry be thought of as a problem-solving or question-answering activity. The logic of such a conception of scientific inquiry has not been studied systematically, however. This paper presents some of the main aspects of the logic on which such a conception of science is based. That logic is called in this paper model-oriented logic, and it is suggested that one can systematically study optimal questioning (...) strategies with it. (shrink)

_The Logic of Our Language_ teaches the practical and everyday application of formal logic. Rather than overwhelming the reader with abstract theory, Jackson and McLeod show how the skills developed through the practice of logic can help us to better understand our own language and reasoning processes. The authors’ goal is to draw attention to the patterns and logical structures inherent in our spoken and written language by teaching the reader how to translate English sentences into formal symbols. Other logical (...) tools, including truth tables, truth trees, and natural deduction, are then introduced as techniques for examining the properties of symbolized sentences and assessing the validity of arguments. A substantial number of practice questions are offered both within the book itself and as interactive activities on a companion website. (shrink)