Fallacies are things people commit, and when they commit them they do something wrong. What kind of activities are people engaged in when they commit fallacies, and in what way are they doing something wrong? Many different things are called fallacies. The diversity of the use of the concept of a fallacy suggests that we are dealing with a family of cases not related by a common essence. However, we suggest a simple account of the nature of fallacies which encompasses (...) them all, viz., the term “fallacy” is our most general term for criticizing any general procedure used for the fixation of beliefs that has an unacceptably high tendency to generate false or unfounded beliefs, relative to that method of fixing beliefs. Very different sorts of things called fallacies are examined in the light of this account, e.g., denying the antecedent, circular arguments, so-called informal fallacies, and propositions said to be fallacies. We do not provide a theory of fallacies. Still, on our account pretty much all of those things that have been called fallacies are fallacies, and they have been called fallacies for pretty much the same reasons. (shrink)

A comprehensive introduction to formal logic, Logic and Philosophy: A Modern Introduction is a rigorous yet accessible text, appropriate for students encountering the subject for the first time. Abundant, carefully crafted exercise sets accompanied by a clear, engaging exposition build to an exploration of sentential logic, first-order predicate logic, the theory of descriptions, identity, relations, set theory, modal logic, and Aristotelian logic. And as its title suggests, Logic and Philosophy is devoted not only to logic but also to the philosophical (...) debates that led to the development of the field. Much new material has been added for the 13th edition. An introduction to set theory and its relationship to logic and mathematics, including philosophical issues, is now part of Chapter 13. Chapter 15 is an introduction to modal logic and Kripke semantics, concluding with a discussion of philosophical problems with any logical accommodation of modalities. Instructors who do not wish to present proof methods will find chapters on truth trees for both sentential and first-order logic, and a presentation of trees for modal logic. Special features of this text include presentations of the history of logic, alternatives to traditional methods of conditional and indirect proof, and a discussion of semantic problems with universal and existential instantiations. Throughout, the authors are sensitive to philosophical issues that arise from the relationship between ordinary language, symbolic logic, and justifications for the syntax and semantics of the various symbolic languages. Discussions range from the justification of the truth table for the sentential rendering of if... then statements to semantic and syntactic paradoxes, including some troubling paradoxes that arise in ordinary language (e.g., the so-called hangman or surprise quiz paradox). Logic and Philosophy includes ample material for a one-semester or two-semester course and provides a thorough preparation for more advanced logic courses. (shrink)

Many philosophers agree with Socrates that it is not possible to perform an akratic action consciously and freely. They take this view because they assimilate the internal irrationality of such a performance to the internal irrationality of drawing a theoretical conclusion which contadicts one's premisses. This article develops some arguments against that assimilation. The extreme cost of theoretical self-contradiction is forming the belief both that something is so and that it is not so. This is impossible for anyone who understands (...) what he is doing, and the impossibility can be explained: nothing could conceivably make such a conjunction of beliefs true. But the conjunction of a value-judgement judgment and an action that gets against it is different. Although it too is internally irrational, there is no property like truth which the value-judgement and his action ought both to possess, but cannot both possess. This article proposes a different model for akratic action, which might serve as a basis for disagreement with Socrates' view of it. (shrink)

v. 1. The collective use and evolution of concepts.

Erkenntnis und Irrtum. Skizzen zur Psychologie der Forschung. Von E. MACH Emer. Professor an der Unlversltlt Wlen. LEIPZIG Verlag von Johann Ambrosius Barth 1905. INTRODUCTION XIII On a number of occasions Mach expressed the sentiment, especially in his correspondence, that America was the land of intellectual freedom and opportunity, the coming frontier for a new radical empiricism that would help to wash metaphysics out of philosophy. In 1901 he sponsored the German edition of Concepts and Theories of Modern Physics (1881) (...) 2 by J. B. Stallo, Cincinnati lawyer and philosopher. Mach warmly endorsed Stallo's book because his scientific aims so closely approximated his own, and because Stallo rejected the latent metaphysical elements and concealed ontological assumptions of the mechanical-atomistic inter­ pretation of the world. The second edition of Wiirmelehre was dedicated to Stallo in 1900. The fourth edition of Populiir-wissenschaftliche Vorlesungen (1910), containing seven new essays, was dedicated to Harvard Professor of physiology, philosophY, and psychology, William James. Mach had a strong intellectual affinity for James' pragmatism because, like himself, he recognized that James had come to radically empirical views from science. Both men took pure pre-conceptualized experience, from which the mental and physical predicates of experience are composed, to be neutral rather than real, unreal, objective or subjective. (shrink)

Psychologism is the view that practical reasons are psychological states. It is widely thought that psychologism is supported by the following principle governing explanation: TF. The difference between false and true beliefs on A's part cannot alter the form of the explanation which will be appropriate to A's actions. (TF) seems to imply that we always need to cite agents' beliefs when explaining their actions, no matter whether those beliefs are true or false. And this seems to vindicate psychologism. I (...) argue, however, that the standard argument for psychologism which includes (TF) as a premise in fact fails to establish its intended conclusion. As a result, the overall case for psychologism is not as strong as it may initially seem. (shrink)

Several of the so-called “fallacies” in Aristotle are not in fact mistaken inference-types, but mistakes or breaches of rules in the questioning games which were practiced in the Academy and in the Lyceum. Hence the entire Aristotelian theory of “fallacies” ought to be studied by reference to the author's interrogative model of inquiry, based on his theory of questions and answers, rather than as a part of the theory of inference. Most of the “fallacies” mentioned by Aristotle can in fact (...) be diagnosed by means of the interrogative model, including petitio principii, multiple questions, “babbling’, etc., and so can Aristotle's alleged anticipation of the fallacy of argumentum ad hominem. The entire Aristotelian conception of inquiry is an interrogative one. Deductive conclusions caught Aristotle's attention in the form of answers that every rational interlocutor must give, assuming only his own earlier answers. Several features of Aristotle's methodology can be understood by means of the interrogative model, including the role of endoxa in it. Theoretically, there is also considerable leeway as to whether “fallacies” are conceived of as mistakes in questioning or as breaches of the rules that govern questioning games. (shrink)

Starting from a concept of reasonableness as well-consideredness, it is discussed in what way science could serve as a model for reasonable argumentation. It turns out that in order to be reasonable two requirements have to be fulfilled. The argumentation should comply with rules which are both problem-valid and intersubjectively valid. Geometrical and anthropological perspectives don't meet these criteria, but a critical perspective does. It is explained that a pragma-dialectical approach to argumentation which agrees with this critical perspective is indeed (...) problem-valid and that strong pragmatic and utilitarian arguments can be given for its intersubjective validity. Thus, conventional validity is promoted for a code of conduct for discussants who want to resolve their disputes reasonably by way of a critical discussion. (shrink)

I explore a distinction that is philosophically significant but rarely a cynosure. The distinction is betvveen fallacies and logical errors, and I approach it by advancing overlooked albeit deleterious logical errors that are not fallacies but that fall squarely within the purview of Critical Thinking if not also Informal Logic. One key claim to emerge is that these logical errors -- just as basic and thought-impeding as the fallacies -- demand that we take a hard look at what is and (...) what should be guiding our activity in teaching such courses. Another is that although philosophers appeal to the notion of logical error in their explications of fallacies, the former notion is anything but clear and indeed usually explained in terms of the latter. Yet another is that the distinction illustrates why the oft encountered “false premise or bad inference” account of how thinking can go bad is oversimplified. (shrink)