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 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)

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)

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)

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)

This new and expanded edition of The Logic of Real Arguments explains a distinctive method for analysing and evaluating arguments. It discusses many examples, ranging from newspaper articles to extracts from classic texts, and from easy passages to much more difficult ones. It shows students how to use the question 'What argument or evidence would justify me in believing P?', and also how to deal with suppositional arguments beginning with the phrase 'Suppose that X were the case.' It aims (...) to help students to think critically about the kind of sustained, theoretical arguments which they commonly encounter in the course of their studies, including arguments about the natural world, about society, about policy, and about philosophy. It will be valuable for students and their teachers in a wide range of disciplines including philosophy, law and the social sciences. (shrink)

This article discusses various dangers that accompany the supposedly benign methods in behavioral evoltutionary biology and evolutionary psychology that fall under the framework of "methodological adaptationism." A "Logic of Research Questions" is proposed that aids in clarifying the reasoning problems that arise due to the framework under critique. The live, and widely practiced, " evolutionary factors" framework is offered as the key comparison and alternative. The article goes beyond the traditional critique of Stephen Jay Gould and Richard C. (...) Lewontin, to present problems such as the disappearance of evidence, the mishandling of the null hypothesis, and failures in scientific reasoning, exemplified by a case from human behavioral ecology. In conclusion the paper shows that "methodological adaptationism" does not deserve its benign reputation. (shrink)

Prior to Kripke's seminal work on the semantics of modal logic, McKinsey offered an alternative interpretation of the necessity operator, inspired by the Bolzano-Tarski notion of logical truth. According to this interpretation, `it is necessary that A' is true just in case every sentence with the same logical form as A is true. In our paper, we investigate this interpretation of the modal operator, resolving some technical questions, and relating it to the logical interpretation of modality and some (...) views in modal metaphysics. In particular, we present an hitherto unpublished solution to problems 41 and 42 from Friedman's 102 problems, which uses a different method of proof from the solution presented in the paper of Tadeusz Prucnal. (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)

What methodological approaches do research programs use to investigate the world? Elisabeth Lloyd’s Logic of Research Questions (LRQ) characterizes such approaches in terms of the questions that the researchers ask and causal factors they consider. She uses the Logic of Research Questions Framework to criticize adaptationist programs in evolutionary biology for dogmatically assuming selection explanations of the traits of organisms. I argue that Lloyd’s general criticism of methodological adaptationism is an artefact of the impoverished LRQ. (...) My Ordered Factors Proposal extends the LRQ to characterize approaches with sequences of questions and factors. I highlight the importance that ordering one’s investigation plays in approaches at the level of adaptationism by analyzing two research programs in community ecology: competitionists and neutralists. Competitionists and neutralists take opposed starting points and use explanatory and developmental heuristics to consider more factors in due time. On the Ordered Factors Proposal, these approaches are not only the ecological factors they are open to considering but also the order in which they will consider them. My disagreement with Lloyd’s over how to characterize methodological approaches reflects different views about methodological monism and pluralism. (shrink)

Say that two sentences are factually equivalent when they describe the same facts or situations, understood as worldly items, i.e. as bits of reality rather than as representations of reality. The notion of factual equivalence is certainly of central interest to philosophical semantics, but it plays a role in a much wider range of philosophical areas. What is the logic of factual equivalence? This paper attempts to give a partial answer to this question, by providing an answer the following, (...) more specific question: Given a standard propositional language with negation, conjunction and disjunction as primitive operators, which sentences of the language should be taken to be factually equivalent by virtue of their logical form? The system for factual equivalence advocated in this paper is a proper fragment of the first-degree system for the logic of analytic equivalence put forward in the late seventies by R. B. Angell. I provide the system with two semantics, both formulated in terms of the notion of a situation’s being fittingly described by a linguistic item. In the final part of the paper I argue, contra a view I defended in my “Grounding and Truth-Functions”, that the logic for factual equivalence I advocate here should be preferred to Angell’s logic if one wishes to follow the general conception of the relationships between factual equivalence and the notion of grounding put forward in the 2010 paper. (shrink)

This book is a thorough study of the question posed by Kant, For what can a human being rationally hope? It offers a detailed commentary on Kant's seminal work, Religion Within the Limits of Reason Alone, as well as an original development of the logic of three of Kant's basic ideas: ambivalence, ignorance, and hope. Sophisticated analytic techniques, including symbolic logic, are applied to this conceptual matrix. The result is a striking case for the transformation of world society (...) into a Kingdom of Ends of individuals and a peaceful League of Nations. (shrink)

The present study starts from the question if there can be any logic of religion. The answer is affirmative for logic in a wide sense. The attempts from the logic of beliefs account for this. However, the study focuses on the specific of the logic of religious terms, a less approached domain by logicians and philosophers. In this line issues like those of the logic of analogy, of the distinctions between the specific, general and total (...) content of terms, between logical distributive and collective conjunctions, etc are brought into discussion. In the end, dogmatic concepts are analyzed, as the core of religious concepts. (shrink)

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.

When one thinks—knows, believes, imagines—that something is the case, one’s thought has a topic: it is about something, towards which one’s mind is directed. What is the logic of thought, so understood? This book begins to explore the idea that, to answer the question, we should take topics seriously. It proposes a hyperintensional account of the propositional contents of thought, arguing that these are individuated not only by the set of possible worlds at which they are true, but also (...) by their topic: what they are about. The book then builds epistemic, doxastic, probabilistic, and conditional logics based on this view. It applies them to issues ranging from dogmatism, scepticism, and epistemic fallibilism, to imagination and suppositional reasoning, belief revision, framing effects, and the acceptability of indicative conditionals. (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)

In this chapter, we begin by sketching in the broadest possible strokes the ideas behind two formal systems that have been introduced with to goal of explicating the ways in which reasons interact to support the actions and conclusions they do. The first of these is the theory of defeasible reasoning developed in the seminal work of Pollock; the second is a more recent theory due to Horty, which adapts and develops the default logic introduced by Reiter to provide (...) an account of reasons. However, the implementations are complex enough, in both cases, to prevent anything more than this sketch. And we would not want to give the impression that we think that work on the logic of reasons must follow the path mapped out in either of these theories—indeed, we feel that the field is wide open. In the remainder of the chapter, therefore, will concentrate on a number of issues bearing on the logic of reasons that are either not treated in the work of Pollock and Horty, or whose treatment there is, we feel, either inadequate or incomplete. These are: first, the question of whether it is necessary to understand logical interactions among reasons themselves, rather than simply between reasons and the actions or conclusions they support, and if so, what principles might govern these interactions; second, priority relations among reasons and the notion of reason accrual; and third, some problems posed by undercutting defeat. (shrink)

Interest in philosophical anthropology in the early twelfth century was limited to the logical question of how to think and speak about dead humans. This question was prompted by the logic of living and dead humans based on the doctrine of substance found in Aristotle’s Categories and in the division of substance, as outlined by Porphyry to exemplify the logic of genus and species relations in the Isagoge. Abelard held the view that there is no such thing as (...) a dead human, and this provoked an intense response from his contemporaries. Abelard’s contemporaries, including Alberic of Paris and other anonymous authors, mounted a number of arguments against Abelard’s views. The stakes were high for them: as realists about species and genera, Abelard’s denial that there are dead humans threatened their entire interpretation of the structure of species and genera, and thereby their theory of universals. (shrink)

There are three distinct questions associated with Simpson's paradox, (i) Why or in what sense is Simpson's paradox a paradox? (ii) What is the proper analysis of the paradox? (iii) How one should proceed when confronted with a typical case of the paradox? We propose a "formar" answer to the first two questions which, among other things, includes deductive proofs for important theorems regarding Simpson's paradox. Our account contrasts sharply with Pearl's causal (and questionable) account of the first (...) two questions. We argue that the "how to proceed question?" does not have a unique response, and that it depends on the context of the problem. We evaluate an objection to our account by comparing ours with Blyth's account of the paradox. Our research on the paradox suggests that the "how to proceed question" needs to be divorced from what makes Simpson's paradox "paradoxical.". (shrink)