Applied Logic presents logic as a relevant tool for interpreting arguments, not simply as an abstract discipline such as mathematics or physics. Through English-language arguments that are debated today—health care, economic problems, AIDS, and so on—the author strives to give students an appreciation of logic's applicability. An appendix provides answers to selected exercises. Applied Logic and the Instructor's Manual will be of great value to those teaching elementary logic.

Logic is a celebrated representation language because of its formal generality. But there are two senses in which a logic may be considered general, one that concerns a technical ability to discriminate between different types of individuals, and another that concerns constitutive norms for reasoning as such. This essay embraces the former, permutation-invariance conception of logic and rejects the latter, Fregean conception of logic. The question of how to apply logic under this pure invariantist view (...) is addressed, and a methodology is given. The pure invariantist view is contrasted with logical pluralism, and a methodology for applied logic is demonstrated in remarks on a variety of issues concerning non-monotonic logic and non-monotonic inference, including Charles Morgan’s impossibility results for non-monotonic logic, David Makinson’s normative constraints for non-monotonic inference, and Igor Douven and Timothy Williamson’s proposed formal constraints on rational acceptance. (shrink)

Theory of Mind (ToM), the cognitive capacity to attribute internal mental states to oneself and others, is a crucial component of social skills. Its formal study has become important, witness recent research on reasoning and information update by intelligent agents, and some proposals for its formal modelling have put forward settings based on Epistemic Logic (EL). Still, due to intrinsic idealisations, it is questionable whether EL can be used to model the high-order cognition of ‘real’ agents. This manuscript proposes (...) a framework that takes visibility, memory, perspective and communication as the main factors underpinning mental attributions. This is more in-line with findings in cognitive science and allows us to model well-known False-Belief Tasks that are typically used in testing people's ToM. We discuss some of the framework's technical features, arguing why it does justice to empirical observations. (shrink)

This instructor's manual, to accompany Applied Logic, contains answers to the exercises found in the text and a workbook useful for preparing students for exams. The text itself presents logic as a relevant tool for interpreting arguments, not simply as an abstract discipline such as mathematics or physics. Through English-language arguments that are debated today—health care, economic problems, AIDS, and so on—the author strives to give students an appreciation of logic's applicability. This book will be of (...) interest to those teaching elementary logic. (shrink)

Kant identifies knowledge [Wissen], belief [Glaube], and opinion [Meinung] as our three primary modes of “holding-to-be-true” [Fürwahrhalten]. He also identifies opinion as making up the greatest part of our cognition. After a preliminary sketch of Kant’s system of propositional attitudes, this paper will explore what he says about the norms governing opinion and empirical hypotheses. The final section will turn to what, in the Critique of Pure Reason and elsewhere, Kant refers to as “General Applied Logic”. It concerns (...) the “contingent conditions of the subject, which can hinder or promote” good inquiry; and, though rarely mentioned in the secondary literature, it offers Kant’s methodological alternative to the traditional epistemological goal of finding “a sufficient and at the same time general criterion of truth”. (shrink)

This classic text, written by philosopher and mathematician William Thomson, presents a systematic exposition of the laws of thought and their role in science, logic, and philosophy. The book is still widely used in philosophy and mathematics courses today. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. (...) Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

Contemporary logicians have expanded upon the old notions of psychologism in logic and proposed new, weakened versions of it. Those weakened versions postulate that psychologistic logic does not have to inform about the ontology or metaphysics of reasoning. Instead, logic applied in cognitive science could serve as one of many paradigms for making empirical predictions about the observable process of human reasoning. The purpose of this article is to entertain this notion and answer the question: what (...) properties should a logical system formally representing actual human reasoning have? Based on the existing evidence from cognitive science and neuroscience we identified three potential candidates: context-sensitivity (satisfied for example by adaptive logics), content-sensitivity (satisfied by non-Fregean logics) and probabilism (satisfied for example by fuzzy logics). (shrink)

This special issue of the Journal of Applied Logics deals with the logical aspects of the concept of God. It contains the following articles: Logic and the Concept of God, by Stanisław Krajewski and Ricardo Silvestre; Mathematical Models in Theology. A Buber-inspired Model of God and its Application to “Shema Israel”, by Stanisław Krajewski; Gödel’s God-like Essence, by Talia Leven; A Logical Solution to the Paradox of the Stone, by Héctor Hernández Ortiz and Victor Cantero; No New Solutions (...) to the Logical Problem of the Trinity, by Beau Branson; What Means ‘Tri-’ in ‘Trinity’ ? An Eastern Patristic Approach to the ‘Quasi-Ordinals’, by Basil Lourié; The Éminence Grise of Christology: Porphyry’s Logical Teaching as a Cornerstone of Argumentation in Christological Debates of the Fifth and Sixth Centruies, by Anna Zhyrkova; The Problem of Universals in Late Patristic Theology, by Dirk Krasmüller; Intuitionist Reasoning in the Tri-unitrian Theology of Nicolas of Cues, by Antonino Drago. (shrink)

This Is A New Release Of The Original 1883 Edition.

Twenty-four U.S. states have enacted HIV exposure laws that prohibit HIV-positive persons from engaging in sexual activities with partners to whom they have not disclosed their HIV-status. From a public health perspective, HIV serostatus exposure laws can be viewed as structural interventions that seek to limit the spread of HIV by acting at the policy level. A central premise of these laws is that informed partners are more likely to protect themselves by declining sex, by substituting less risky activities for (...) higher-risk ones, or by using condoms, than are uninformed partners. However, the effectiveness of these laws at preventing HIV transmission is not known.There is little standardization among existing HIV exposure laws, which vary substantially with respect to the sexual activities that are prohibited without prior serostatus disclosure. Among the strictest laws are those in Arkansas, Michigan, New Jersey, and Ohio which mandate disclosure prior to almost any type of sexual contact. (shrink)

Elementary Applied Symbolic Logic was first published by Prentice-Hall in 1976. It went through two editions with them, then had a successful classroom run of 25 years by various publishers, before it finally went out of print in 2001.I am reviving it here, because during its run it acquired a reputation as an outstanding textbook for getting students to understand symbolic logic.I immodestly believe it is the best textbook ever written on the subject.------------This is a book on (...) applied symbolic logic. It provides the bridge between statements and arguments in English, and their formal counterparts in symbolic logic. Extensive exercises are given, illustrating how different natural-language concepts can correspond to the same symbolism, and how English sentences may be translated into formulae. Translation is heavily emphasized.It is intended to make learning symbolic logic (relatively) easy, by starting out with very basics and progressing from there a step at a time, building on what came before. I tried to make it as close to a self-teaching text as I could manage. It has two major divisions: Propositional Logic and Quantifier Logic.The first starts with propositions and truth-values, then truth-tables for evaluating the status of statements and arguments. It then moves to natural deduction, with rules for making inferences and transformations. Procedures are given for proving both validity and invalidity.Exercises increase in complexity as things move along. Solutions to selected exercises are included at the back of the book.Quantifier Logic starts with Monadic predicate logic, involving only single-place predicates ("properties"). It starts with singular statements and propositional functions, then moves to statements containing a single universal or existential quantifier, then to statements and arguments involving multiple quantifiers. It covers inferences using quantificational inference and transformation rules, and gives methods of invalidity proof.Its second half goes into polyadic predicates ("relations") of various degrees, moves on to identity, and finally to definite descriptions.Appendices on various related and supplementary topics are included at the end. The original appendix on Completeness and Consistency was complicated and confusing. It has been deleted, and replaced with an addendum at the end. (shrink)

The word ‘logic’ has many senses. Here we will understand it as meaning an account of what follows from what and why. With contemporary methodology, logic in this sense – though it may not always have been thought of in this way – is a branch of applied mathematics. This has various implications for how one understands a number of issues concerning validity. In this paper I will explain this perspective of logic, and explore some of (...) its consequences with respect to the notion of logical form. (shrink)

Because of the problems associated with ecological concepts, generalizations, and proposed general theories, applied ecology may require a new "logic" of explanation characterized neither by the traditional accounts of confirmation nor by the logic of discovery. Building on the works of Grunbaum, Kuhn, and Wittgenstein, we use detailed descriptions from research on conserving the Northern Spotted Owl, a case typical of problem solving in applied ecology, to (1) characterize the method of case studies; (2) survey its (...) strengths; (3) summarize and respond to its shortcomings; and (4) investigate and defend its underlying "logic". (shrink)

Computability logic (CL) is a recently launched program for redeveloping logic as a formal theory of computability, as opposed to the formal theory of truth that logic has more traditionally been. Formulas in it represent computational problems, "truth" means existence of an algorithmic solution, and proofs encode such solutions. Within the line of research devoted to finding axiomatizations for ever more expressive fragments of CL, the present paper introduces a new deductive system CL12 and proves its soundness (...) and completeness with respect to the semantics of CL. Conservatively extending classical predicate calculus and offering considerable additional expressive and deductive power, CL12 presents a reasonable, computationally meaningful, constructive alternative to classical logic as a basis for applied theories. To obtain a model example of such theories, this paper rebuilds the traditional, classical-logic-based Peano arithmetic into a computability-logic-based counterpart. Among the purposes of the present contribution is to provide a starting point for what, as the author wishes to hope, might become a new line of research with a potential of interesting findings—an exploration of the presumably quite unusual metatheory of CL-based arithmetic and other CL-based applied systems. (shrink)

The proof of Lemma 5 in our paper “Choice Principles in Hyperuniverses” [3], contains an error. In the present note we show that the statement of that lemma is false and hence the Axiom of Choice fails in all κ-hyperuniverses, for uncountable κ. However, a weaker version of Lemma 5 can be proved, which implies that the Linear Ordering Principle holds in all κ-metric κ-hyperuniverses.