A major purpose of this book is to make the post-Hamblin work on fallacies available to a wider audience in a single, convenient volume.

Fallacies are the ‘ideal types of improper inference’, named only because they represent a common or seductive error. Naming them facilitates identification (reducing ‘false negatives’ in argument evaluation), but increases the risk of false positives; it is essentially a cost-effectiveness issue whether to introduce a new name. Statistical fallacies include errors of elementary experimental design, but also conceptual confusions, e.g. of cause with correlation, of association with guilt, where an illicit substitution is made. The focus here is on recent nationwide (...) efforts to replace criteria of merit with correlates of success, in the evaluation of teaching. This involves a number of mistakes, including ‘precipitate decision’, confusing the normative with the descriptive, and using minimax when optimizing or maximin is appropriate, as well as various legal and ethical blunders. (shrink)

Fallacies and Argument Appraisal presents an introduction to the nature, identification, and causes of fallacious reasoning, along with key questions for evaluation. Drawing from the latest work on fallacies as well as some of the standard ideas that have remained relevant since Aristotle, Christopher Tindale investigates central cases of major fallacies in order to understand what has gone wrong and how this has occurred. Dispensing with the approach that simply assigns labels and brief descriptions of fallacies, Tindale provides fuller treatments (...) that recognize the dialectical and rhetorical contexts in which fallacies arise. This volume analyzes major fallacies through accessible, everyday examples. Critical questions are developed for each fallacy to help the student identify them and provide considered evaluations. (shrink)

We are happy to present to the reader the first book of our Applied Logic Series. Walton's book on the fallacies of ambiguity is firmly at the heart of practical reasoning, an important part of applied logic. There is an increasing interest in artifIcial intelligence, philosophy, psychol ogy, software engineering and linguistics, in the analysis and possible mechanisation of human practical reasoning. Continuing the ancient quest that began with Aristotle, computer scientists, logicians, philosophers and linguists are vigorously seeking to deepen (...) our understanding of human reasoning and argumentation. Significant communities of researchers are actively engaged in developing new approaches to logic and argumentation, which are better suited to the urgent needs of today's applications. The author of this book has, over many years, made significant contributions to the detailed analysis of practical reasoning case studies, thus providing solid foundations for new and more applicable formal logical systems. We welcome Doug Walton's new book to our series. (shrink)

This paper offers a solution to the problem of understanding how a fallacious argument can be deceptive by “seeming to be valid”, or (better) appearing to be a better argument of its kind than it really is. The explanation of how fallacies are deceptive is based on heuristics and paraschemes. Heuristics are fast and frugal shortcuts to a solution to a problem that sometimes jump to a conclusion that is not justified. In fallacious instances, according to the theory proposed, this (...) jump overlooks prerequisites of the defeasible argumentation scheme for the type of argument in question. Three informal fallacies, argumentum ad verecundiam , argumentum ad ignorantiam and fear appeal argument, are used to illustrate and explain the theory. (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)

In the pragma-dialectical approach, fallacies are considered incorrect moves in a discussion for which the goal is successful resolution of a dispute. Ten rules are given for effective conduct at the various stages of such a critical discussion (confrontation, opening, argumentation, concluding). Fallacies are discussed as violations of these rules, taking into account all speech acts which are traditionally recognized as fallacies. Special attention is paid to the role played by implicitness in fallacies in everyday language use. It is stressed (...) that identifying and acknowledging fallacies in ordinary discussions always has a conditional character. Differences between the pragma-dialectical perspective, the Standard Treatment, and the formal logic approach to fallacy analysis are discussed. (shrink)

Why are some arguments fallacious? Since argumentation is an intellectual activity that can be performed better or worse, do we evaluate arguments simply in terms of their content, or does it also make sense to evaluate the arguer in light of the content put forward? From a ‘virtue’ approach, I propose understanding fallacies as having some link with intellectual vice. Drawing from recent work by Paul Grice, Linda Zagzebski, Andrew Aberdein, and Douglas Walton, this essay argues that if there is (...) some sense of argumentation where an argument is truth-propagating and not put forward in order to ‘win’, fallacies may be the vicious element in arguments that undermines, most often because the arguer’s goal is only. From this perspective, fallacies may not only be improper ‘moves’ in an argument, but may also reveal something lacking in the arguer’s intellectual character. (shrink)

I will situate the fallacies approach to reasoning with the aim of making it more relevant to contemporary life and thus intellectually significant and valuable as a method for teaching reasoning. This entails a revision that will relegate some of the traditional fallacies to the realm of history and introduce more recently recognized problems in reasoning. Some newly recognized problems that demand attention are revealed by contemporary science studies, which reveal at least two tenacious problems in reasoning that I will (...) explore in this paper. One of these problems is androcentrism, a ubiquitous problem with reasoning that feminists exposed in the twentieth century but that continues to pervade people’s reasoning. The other is biological reductionism in at least two specific forms: genetic determinism and adaptationism. (shrink)

The ad baculum is not a fallacy in an argument, but is offered instead of an argument to put an end to further argument. This claim is the basis for criticizing Michael Wreen's "neo-traditionalism," which yields misreadings of supposed cases of the ad baculum because of its rejection of any consideration of what the person using the ad baculum, or someone who refers to that use as an "argument," is doing. The paper concludes with reflections on the values that should (...) inform talk of a fallacy in an argument such as the one that Wreen is giving. (shrink)

The paper examines Walton‘s concept of fallacy as it develops throughthree stages of his work: from the early series of papers co-authored withJohn Woods; through a second phase of involvement with thepragma-dialectical perspective; and on to the final phase in which heoffers a distinct pragmatic theory that reaches beyond the perceived limitsof the pragma-dialectical account while still exhibiting a debt to thatperspective and the early investigations with Woods. It is observed how Walton‘s model of fallacy is established in distinction to (...) its competitors,and its various problems and successes are discussed. (shrink)

The basic question of this monograph is: how should we go about judging arguments to be reasonable or unreasonable? Our concern will be with argument in a broad sense, with realistic arguments in natural language. The basic object will be to engage in a normative study of determining what factors, standards, or procedures should be adopted or appealed to in evaluating an argument as "good," "not-so-good," "open to criticism," "fallacious," and so forth. Hence our primary concern will be with the (...) problems of how to criticize an argument, and when a criticism is reasonably justified. (shrink)

Van Eemeren and Houtlosser view fallacies as “derailments of strategic maneuvering” that go against a norm for critical reasonableness. What is to happen if such a derailment is perceived to have taken place? Krabbe (2003) and Jacobs (2000) have discussed the possibilities for continuing the argumentative exchange in a constructive way. Starting from their proposals, van Eemeren and Houtlosser argue that the party who observes that something has gone wrong should maneuver in such a way that at the same time (...) the derailment is recognized and a “re-railment” takes place that brings the discussion back on track. This means that then a meta-dialogue or sub-discussion develops in which the alleged fallacy is responded to and readjusted appropriately. Although this solution has something in common with both Krabbe’s proposal and Jacobs’ proposal, it differs from Krabbe’s proposal because it does not result in just retracting or maintaining the alleged fallacy and it differs from Jacobs’ proposal because it does not allow for making a move that has the appearance of a counter-fallacy. (shrink)

My One Fallacy theory says there is only one fallacy: equivocation, or playing on an ambiguity. In this paper I explain how this theory arose from rnetaphilosophical concerns. And I contrast this theory with purely logical, dialectical, and psychological notions of fallacy.

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)

Dialectical fallacies are typically defined as breaches of the rules of a regulated discussion between two participants. What if discussions become more complex and involve multiple parties with distinct positions to argue for? Are there distinct argumentation norms of polylogues? If so, can their violations be conceptualized as polylogical fallacies? I will argue for such an approach and analyze two candidates for argumentative breaches of multi-party rationality: false dilemma and collateral straw man.

This chapter contains sections titled: The False Cause Fallacy Hasty Generalizations Failure to Take Context into Account Suppressing Relevant Evidence The Gambler's Fallacy Affirming the Consequent/Denying the Antecedent The Fallacies of Composition and Division Missing the Forest for the Trees.

This chapter focuses on one of the common fallacies in Western philosophy called the subjectivist fallacy (SbF). The SbF occurs when one concludes that something is true for one person (a subject) but not true for another person (another subject), when, in fact, it is true objectively for all persons. SbF is a fallacy of relativism. Relativism, in general, means the truth‐value of a judgment is neither necessary nor universal; however, there are multiple kinds of relativism. SbF is not only (...) a fallacious depiction of relativity; it is also self‐refuting. To avoid this fallacy, one needs to ground arguments with claims that are objective or that hold universally. When the claims on which an argument is based are objectively verifiable or pertain to a set of individuals universally, then the logical necessity of the argument's conclusion may be determined. (shrink)

This chapter focuses on one of the common fallacies in Western philosophy: definist fallacy. The definist fallacy consists of (1) defining one concept in terms of another concept with which it is not clearly synonymous, (2) as the persuasive definition fallacy, defining a concept in terms of another concept in an infelicitous way that is favorable to one's position, or (3) the insistence that a term be defined before it can be used in discussion. The simplest way to not commit (...) any version of this fallacy is to define one's terms credibly! He/she needs to avoid using definitions that are laden with emotion or those that are idiosyncratic. That is, he/she may use more neutral and accepted definitions. If those definitions seem inadequate for his/her purposes, then he/she may argue for his/her definition. (shrink)

An ad hominem fallacy is committed when an individual employs an irrelevant personal attack against an opponent instead of addressing that opponent’s argument. Many discussions of such fallacies discuss judgments of relevance about such personal attacks, and consider how we might distinguish those that are relevant from those that are not. This paper will argue that the literature on bias and testimony can helpfully contribute to that analysis. This will highlight ways in which biases, particularly unconscious biases, can make ad (...) hominem fallacies seem effective, even when the irrelevance is recognized. (shrink)

The fallacy fallacy is either the misdiagnosis of fallacy or the supposition that the conclusion of a fallacy must be a falsehood. This paper explores the relevance of these and related errors of reasoning for the appraisal of arguments, especially within virtue theories of argumentation. In particular, the fallacy fallacy exemplifies the Owl of Minerva problem, whereby tools devised to understand a norm make possible new ways of violating the norm. Fallacies are such tools and so are vices. Hence a (...) similar problem arises with argumentative vices. Fortunately, both instances of the problem have a common remedy. (shrink)

Leading invasion biologists sometimes dismiss critics and criticisms of their field by invoking “the straw man” fallacy. Critics of invasion biology are also labelled as a small group of “naysayers” or “contrarians”, who are sometimes engaging in “science denialism”. Such unfortunate labels can be seen as a way to possibly suppress legitimate debates and dismiss or minimize reasonable concerns about some aspects of invasion biology, including the uncertainties about the geographic origins and complex environmental impacts of species, and the control (...) programs against species perceived as “invasive”. In assessing the quality of the debate in this area, we examine the validity of the use of various strategies, including the “straw man” concept, and explore a range of potential logical fallacies present in some recent prominent discussions about invasion biology and so-called “invasive” species. The goal is to add some clarity to the concepts involved, point out some problematic issues, and improve the quality of the debates as the discussions move forward. (shrink)

We have been oversold on the base rate fallacy in probabilistic judgment from an empirical, normative, and methodological standpoint. At the empirical level, a thorough examination of the base rate literature (including the famous lawyer–engineer problem) does not support the conventional wisdom that people routinely ignore base rates. Quite the contrary, the literature shows that base rates are almost always used and that their degree of use depends on task structure and representation. Specifically, base rates play a relatively larger role (...) in tasks where base rates are implicitly learned or can be represented in frequentist terms. Base rates are also used more when they are reliable and relatively more diagnostic than available individuating information. At the normative level, the base rate fallacy should be rejected because few tasks map unambiguously into the narrow framework that is held up as the standard of good decision making. Mechanical applications of Bayes's theorem to identify performance errors are inappropriate when (1) key assumptions of the model are either unchecked or grossly violated, and (2) no attempt is made to identify the decision maker's goals, values, and task assumptions. Methodologically, the current approach is criticized for its failure to consider how the ambiguous, unreliable, and unstable base rates of the real world are and should be used. Where decision makers' assumptions and goals vary, and where performance criteria are complex, the traditional Bayesian standard is insufficient. Even where predictive accuracy is the goal in commonly defined problems, there may be situations (e.g., informationally redundant environments) in which base rates can be ignored with impunity. A more ecologically valid research program is called for. This program should emphasize the development of prescriptive theory in rich, realistic decision environments. (shrink)

The view that we live in the Anthropocene is increasingly gaining currency across scientific disciplines. Especially in sociology this is said to require a paradigm shift in analysis and theory formation. This article argues that such a conclusion is premature. Owing to a scholastic fallacy – the uncritical transposition of the concept from the natural to the social sciences – Anthropocene lacks analytic clarity and explanatory power evidenced by: a normative overreach that erroneously imagines an idealised world citizenry with collective (...) action capacities; an obfuscation of the unequal distribution of ecological pathologies caused by capitalism; a normative indeterminacy concerning modes of redress; and an abstract ecological universalism offered as moral panacea. The article suggests that sociology needs to address the Anthropocene’s heterogeneity marked by contradictory regional interests and inequalities that neither appeals to social justice or ‘one humanity’ nor an escape into a dissolution of ontological differences between actors and artefacts can redeem. To that end, sociologists are asked to undertake a critical reconstruction of the concept. (shrink)

Lately, a number of referee decisions appear to have reignited the debate over the need to bring more in-game officiating technology into soccer. The fallacies behind the arguments for the inclusion of technology to aid game officials can be narrowed down to those behind current arguments for or against goal-line technology. Both the proponents and opponents of these arguments appear to overemphasise the role of referees to the point of claiming that if refereeing errors could be eliminated in goal-line situations, (...) then the most deserving team would most of the time be expected to win the contest. While we firmly believe that the game of soccer would benefit immensely from infallible officiating, we intend to show that these arguments are founded upon a number of inconspicuous assumptions. First, they assume that goal-line situations can be shown to affect the outcomes of games more than all other game situations. This can easily be shown to be a myth, since goals can be scored from all areas of the playing field. In addition, winning a soccer game, obviously, involves more than just scoring goals. Second, these arguments seem to support the view that referee decisions affect the outcomes of games more than decisions made by players, coaches and managers. This is merely a myth, since one can show that, in light of Cesar Torres's insights, referee involvement in game is limited to regulating situations that demand that the game be restored to its constitutive actualisation. Third, most arguments for goal-line technology tend to support the erroneous view that technology can actually eliminate most ?crucial? human mistakes from sport and, thus, ensure fairness of game outcomes. Such a myth can easily be refuted by reference to numerous cases of inconclusive slow-motion video replays in soccer. Therefore, this paper aims at arguing that, instead of reinforcing the scapegoating of referees and overemphasising the importance of isolated referee decisions to the point of attributing victory or defeat to these ?crucial? decisions, both sides of the goal-line technology debate need to put forth compelling arguments which go beyond the current misguided search for referee infallibility. (shrink)

This article demonstrates the fallacy of legal deduction as a method which is supposed to guarantee the certainty and predictability of the law. The Author asserts that legal deduction is in fact not of a logical nature. Their premises are of an uneven character or else one of them must be created in a non-mechanical way. This in turn makes legal deduction that is comprehended as a mode of inference that is infallible, provided its premises are true / valid nothing (...) more than misunderstanding and fallacy. In addition, in this paper, the outcomes of legal deduction are shown to be highly dependent on the direct and indirect context under the threat of their being utterly absurd. Since the lack of fixity and clarity, these contexts, however, may lead one to madness, i. e. at least unless she or he abandons the idea that only logical types of inferences govern legal deduction and are solely responsible for its outcomes. (shrink)

“Digital footprints” is an attractive, useful, and increasingly popular metaphor for thinking about Big Data. In this essay, I elaborate on this metaphor to highlight three relatively basic fallacies in the way we tend to think about Big Data: first, that they contain information on complete populations, or “N = all”; second, that they contain recordings of naturalistic behavior; and third, that they can be understood devoid of context.

This paper provides methodological tools and considers the reasons why it is difficult to address the controversial question, “Are fallacies frequent?” After preliminary remarks on the need to clarify the meaning of both ‘fallacy’ and ‘frequency,’ this paper shows that the emphasis on whether fallacies occur frequently is recent and bound to contemporary definitions that make it a necessary condition. Then, it discusses three different, debated empirical approaches that are intended to support the claim that fallacies are frequent. All of (...) them raise doubts or objections or are even controversial from a methodological point of view. Ultimately, more empirical research is needed to answer this question. (shrink)

This chapter focuses on one of the common fallacies in Western philosophy, etymological fallacy (EF). To understand the EF fully, it is important to break down the word etymology, which is a practice that in itself informs the conversation surrounding the fallacy. EF is a willful use of a former definition of a word that has changed meaning and/or developed new connotations because the change does not benefit the one committing the fallacy. To avoid committing the EF, individuals should approach (...) language as they would a scientific process: they may hypothesize the word means X, but after further research and consideration, realize that indeed a word now means Y. Either way, the changing nature of language must be considered and individuals should be learned enough and flexible enough to communicate within the time and culture they inhabit. Clinging to etymons while ignoring the evolution and everyday use of language is neither logical nor truthful. (shrink)

This chapter focuses on one of the common fallacies in Western philosophy: the moralistic fallacy. The moralistic fallacy occurs when one concludes that something is a particular way because it should or ought to be that way. Alternatively, this fallacy occurs when one concludes that something cannot be a particular way because it should not or ought not be that way. The moralistic fallacy is often described as the reverse of the is/ought fallacy, wherein one reasons fallaciously that because things (...) are a particular way, they ought to be that way. Variations of the moralistic fallacy occur whenever any normative claim is used to justify a factual claim about the world, and so the pattern of fallacious reason central to the moralistic fallacy can also be found in legal reasoning, prudential reasoning, or reasoning regarding proper etiquette, aesthetics, humor, or appropriate emotional responses. (shrink)

The respect for one’s conscience is rooted in a broader respect for the human person. The conscience represents a person’s ability to identify the values and goods that inform her moral identity. Ignoring or overriding a person’s conscience can lead to significant moral and emotional distress. Refusals to respect a person’s conscientious objection to cases of killing are a source of incisive distress, since judgments that it is impermissible to kill so-and-so are typically held very strongly and serve as central (...) moral commitments in one’s moral identity. I think it is wrong for a college basketball coach to pay his players, but I think it is really wrong to kill people. This article argues that any and all arguments for not respecting a conscientious objection to abortion commit a deontic fallacy. Briefly, arguments for the permissibility of abortion are structurally such that abortion is at best permissible, not obligatory. Now, arguments to justify overriding or ignoring a person’s objection to performing action (α) must understand action (α) as being obligatory. Thus, arguments for ignoring conscientious objections to performing abortion are incongruent with the actual philosophical justifications for abortion. Such arguments, then, commit a deontic fallacy. (shrink)

The paper critically investigates the pragma-dialectics of van Eemeren and Grootendorst, particularly the treatment of fallacies. While the pragma-dialectieians claim that dialectics combines the logical and rhetorical approaches to argumentation, it is argued here that the perspective relies heavily on rhetorical features that have been suppressed in the account and that overlooking these features leads to significant problems in the pragma-dialectical perspective. In light of these problems, the author advocates turning attention to a rhetorical account which subsumes the logical and (...) dialectical. (shrink)

The so-called New Theory of Reference (Marcus, Kripke etc.) is inspired by the insight that in modal and intensional contexts quantifiers presuppose nondescriptive unanalyzable identity criteria which do not reduce to any descriptive conditions. From this valid insight the New Theorists fallaciously move to the idea that free singular terms can exhibit a built-in direct reference and that there is even a special class of singular terms (proper names) necessarily exhibiting direct reference. This fallacious move has been encouraged by a (...) mistaken belief in the substitutional interpretation of quantifiers, by the myth of thede re reference, and a mistaken assimilation of direct reference to ostensive (perspectival) identification. Thede dicto vs.de re contrast does not involve direct reference, being merely a matter of rule-ordering (scope).The New Theorists' thesis of the necessity of identities of directly referred-to individuals is a consequence of an unmotivated and arbitrary restriction they tacitly impose on the identification of individuals. (shrink)

Three fallacies in the rationality debate obscure the possibility for reconciling the opposed camps. I focus on how these fallacies arise in the view that subjects interpret their task differently from the experimenters (owing to the influence of conversational expectations). The themes are: first, critical assessment must start from subjects' understanding; second, a modal fallacy; and third, fallacies of distribution.

The taxonomy and analysis of fallacies in Aristotle's Sophistical Refutations pre-date the formal logic of his Prior Analytics A4-6. Of the 64 fully described examples of ?sophistical refutations? which are fallacious because they are only apparently valid, 49 have the wrong number of premisses or the wrong form of premiss or conclusion for analysis by the Prior Analytics theory of the categorical syllogism. The rest Aristotle either frames so that they do not look like categorical syllogisms or analyses in a (...) quite different way than by categorical syllogistic. (shrink)

The dialectical approach to teaching critical thinking is centred on a comparative evaluation of contending arguments, so that generally the strength of an argument for a position can only be assessed in the context of this dialectic. The identification of fallacies, though important, plays only a preliminary role in the evaluation to individual arguments. Our approach to fallacy identification and analysis sees fallacies as argument patterns whose persuasive power is disproportionate to their probative value.

Robert Kimball, in “What’s Wrong with Argumentum Ad Baculum?” (Argumentation, 2006) argues that dialogue-based models of rational argumentation do not satisfactorily account for what is objectionable about more malicious uses of threats encountered in some ad baculum arguments. We review the dialogue-based approach to argumentum ad baculum, and show how it can offer more than Kimball thinks for analyzing such threat arguments and ad baculum fallacies.

The paper argues that the two best known formal logical fallacies, namely denying the antecedent (DA) and affirming the consequent (AC) are not just basic and simple errors, which prove human irrationality, but rather informational shortcuts, which may provide a quick and dirty way of extracting useful information from the environment. DA and AC are shown to be degraded versions of Bayes’ theorem, once this is stripped of some of its probabilities. The less the probabilities count, the closer these fallacies (...) become to a reasoning that is not only informationally useful but also logically valid. (shrink)

A leading theoretical framework for naturalistic explanation of mind holds that we explain the mind by positing progressively "stupider" capacities ("homunculi") until the mind is "discharged" by means of capacities that are not intelligent at all. The so-called homuncular fallacy involves violating this procedure by positing the same capacities at subpersonal levels. I argue that the homuncular fallacy is not a fallacy, and that modern-day homunculi are idle posits. I propose an alternative view of what naturalism requires that reflects how (...) the cognitive sciences are actually integrating mind and matter. (shrink)

This chapter examines the hazards and pseudohazards of thought experiment. It attacks most skepticism about thought experiment as arbitrary. It argues that once the standards that are customary for compasses, stethoscopes, and other testing devices are applied, thought experiments measure up. They should be used as part of a diversified portfolio of techniques. Although all these devices are individually susceptible to abuse, fallacy, and error, they provide a network of cross-checks that make for impressive collective reliability.

If people believe that some property is true of all members of a class such as sofas, then they should also believe that the same property is true of all members of a conjunctively defined subset of that class such as uncomfortable handmade sofas. A series of experiments demonstrated a failure to observe this constraint, leading to what is termed the inverse conjunction fallacy. Not only did people often express a belief in the more general statement but not in the (...) more specific, but also when they accepted both beliefs, they were inclined to give greater confidence to the more general. It is argued that this effect underlies a number of other demonstrations of fallacious reasoning, particularly in category-based induction. Alternative accounts of the phenomenon are evaluated, and it is concluded that the effect is best interpreted in terms of intensional reasoning [Tversky, A., & Kahneman, D.. Extensional versus intuitive reasoning: the conjunction fallacy in probability judgment. Psychological Review, 90, 293-315.]. (shrink)

This chapter focuses on one of the common fallacies in Western philosophy, 'existential fallacy'. This fallacy occurs when we erroneously suppose some class or group has members. In other words, statements may be true about classes or groups even if no members of the class or group exist. In terms of syllogistic argumentation, this is a formal fallacy in that it results when the premises are universal in quantification and the conclusion is particular. In the history of logic, the existential (...) fallacy may be traced to dictum de omni, which refers to the principle in Aristotelian logic that whatever is said universally of a subject is said of everything that is contained under such a subject. In order to avoid this fallacy, one should look for empirical verification of the existence of whatever entity may be in question. (shrink)

Milton Friedman's article, The Social Responsibility of Business Is To Increase Its Profits, owes its appeal to the rhetorical devices of simplicity, authority, and finality. More careful consideration reveals oversimplification and ambiguity that conceals empirical errors and logical fallacies. It is false that business does, or would, operate exclusively in economic terms, that managers concentrate obsessively on profitability, and that ethics can be marginalized. These errors reflect basic contradictions: an apolitical political base, altruistic agents of selfishness, and good deriving from (...) greed. (shrink)