lt is now commonplace in fallacy inquiry for many of the traditional informal fallacies to be viewed as reasonable or nonfallacious modes of argument. Central to this evaluative shift has been the attempt to examine traditional fallacies within their wider contexts of use. However, this pragmatic turn in fallacy evaluation is still in its infancy. The true potential of a contextual approach in the evaluation of the fallacies is yet to be explored. I examine how, in the context of scientific (...) inquiry, certain traditional fallacies function by conferring epistemic gains upon inquiry. Specifically, I argue that these fallacies facilitate the progression of inquiry, particularly in the initial stages ofinquiry when the epistemic context is one of uncertainty. The conception of these fallacies that emerges is that of heuristics of reasoning in contexts of epistemic uncertainty. (shrink)

In this overview article, we first explain what we take informal logic to be, discussing misconceptions and distinguishing our conception of it from competing ones; second, we briefly catalogue recent informal logic research, under 14 headings; third, we suggest four broad areas of problems and questions for future research; fourth, we describe current scholarly resources for informal logic; fifth, we discuss three implications of informal logic for philosophy in particular, and take note ofpractical consequences of a more general sort.

Informal logic has expanded the concept of an 'argument' beyond that presented traditionally by formal logicians-to include arguments as encountered in 'real-life'. Existent definitions of argument structure are argued to be inadequate by failing to fully recognise that, ultimately, arguments have a human source. Accordingly, a new definition is proposed which appeals to relevant cognitive and behavioural factors. The definition retains some traditional concepts, but introduces the term 'supportive' as a modification to 'premiss'. The concept of a 'persuader' is also (...) developed. The definition is argued to capture more fully the intricacies, subtleties and rich diversity of informal arguments. (shrink)

This paper defends the view that the classification of an argument as being deductive ought to rest exclusively upon psychological considerations; specifically, upon whether the argument's author holds certain beliefs. This account is justified on theoretical and pedagogical grounds, and situated within a general taxonomy of competing proposals. Epistemological difficulties involved in the application of psychological definitions are recognized but claimed to be ineliminable from the praetice of argumentation. The paper concludes by discussing embryonic arguments where the author's relevant beliefs (...) are not sufficiently fine-grained so as to accord the argument deductive or inductive status. (shrink)

Argument by analogy has long been regarded as the characteristic way of arguing in ancient Chinese culture. Classic Chinese philosophers not only prefer to use analogy to argue for their own views, but also take efforts to theorize it in a systematic way. This paper aims to provide a careful study on the relevant ideas in ancient China in order to reconstruct the ancient Chinese theory of argument by analogy, and then to reveal some of its distinctive features through a (...) comparison with the Western counterpart account as developed by Aristotle. It is indicated that in ancient China analogical argument was conceived primarily as a way of arguing based on classification, with a unique mechanism of taking and giving according to kind. On that basis, it is argued that although such a characterization captures the logical structure of analogical argument in a similar way to Aristotle, the ancient Chinese theory stresses the foundational role of a particular notion of kind, thus makes the construction and application of analogical arguments become highly flexible and context-sensitive. Moreover, it is also contended that in ancient China the rationale of analogical arguments is explained from a general perspective of kind, relying upon the universal knowledge pertaining to the forming of kinds. Then it is further revealed that, unlike Aristotle who emphasizes the causal links between attributes in the physical world, ancient Chinese thinkers justify analogical argument by appealing to some normative metaphysical and epistemological principles. (shrink)

This paper is a critical analysis of three theories of fallacy, those of Ralph Johnson, of Jaakko Hintikka, and of Robert Fogelin and Timothy Duggan. Although the theories are very different from one another, all oppose the traditional, non-dialectical view of a fallacy as a mistaken inference. The theories are exposed and explained in detail, and then subjected to critical examination. For a variety of reasons, all are found seriously wanting. The mistakes of each suggest that it is better to (...) stay with the traditional view, at least if suitably refined and qualified. (shrink)

If one looks to the current textbook lore for reliable taxonomic and analytical information about the petitio principii, one is met with conceptual disarray and much too much nonsense. The present writers have recently attempted to furnish the beginnings of a theoretical reconstruction of this fallacy which is at once faithful to its formidable complexity yet useful as guide for its detection and avoidance. The fact is that the petitio has had a lengthy and interesting history, and in this paper (...) we shall want to explore certain features of its development, such as it may have been. The principal origins of the concept of circular argument are to be found in Aristotle. The Aristotelian doctrine recurs with variations in the sophismata literature of the middle ages and in logic texts and manuals right up to the present day. (shrink)

It is a received view of the post-Fregean predicate logic that a universal statement has no existential import and thus does not entail its particular (existential) counterpart. This paper takes issue with the view by discussing the trespasser case, which has widely been employed for supporting the view. The trespasser case in fact involves a shift of context. Properly understood, the case provides no support for the received view but rather suggests that we rethink the ‘quantity view’ of the existential (...) import of quantifiers. (shrink)

This article analyses the fallacy of wrenching from context, using the dialectical notions of commitment and implicature as tools. The data, a set of key examples, is used to sharpen the conceptual borderlines around the related fallacies of straw man, accent, misquotation, and neglect of qualifications. According to the analysis, the main characteristics of wrenching from context are the manipulation of the meaning of the other’s statement through devices such as the use of misquotations, selective quotations, and quoting out of (...) context. The theoretical tools employed in the analysis are pragmatic theories of meaning and a dialectical model of commitment, used to explain how and why a standpoint is distorted. The analysis is based on a conception of fallacies as deceptive strategic moves in a game of dialogue. As a consequence, our focus is not only on misquotations as distortions of meaning, but on how they are used as dialectical tools to attack an opponent or win a dispute. Wrenching from context is described as a fallacy of unfairly attributing a commitment to another party that he never held. Its power as a deceptive argumentation tactic is based on complex mechanisms of implicit commitments and on their misemployment to improperly suggest an attribution of commitment. (shrink)

This paper presents an analysis of argumentation in direct-to-consumer health product ads in Newsweek that brings out special features of the arguments used in the ads, including practical reasoning, chained arguments, enthymemes, and prolepsis. A way to help overcome deficiencies in techniques of tailored health communication in consumer health informatics is shown by using argumentation schemes, argument visualisation tools, and dialogue models to frame these persuasive communication messages. The evidence collected is shown to be useful to allow the health informatics (...) communicator and the person to whom message was directed to interact in a dialogue format where arguments can be put forward by both parties in a way that responds to the previous arguments and questions of the other party. (shrink)

We argue that Hilary Putnam's pragmatism provides an epistemological perspective which can help us understand--and can positively inform--the development of informal logic.

This article aims tt providing some conceptual tools for dealing adequately with relevance in argumentative discourse. For this purpose, argumentative relevance is defined as a functional interactional relation between certain elements in the discourse. In addition to the distinction between interpretive and evaluative relevance that can be traced in the literature, analytic relevance is introduced as an intermediary concept. In order to classify the various problems of relevance arising in interpreting, analyzing and evaluating argumentative discourse, a taxonomy is proposed in (...) which the concept of relevance is differentiated along three co-ordinate dimensions: object, domain and aspect. With the help of this taxonomy, it can be shown that the problems of evaluative relevance with which the standard approach to fallacies cannot satisfactory deal can be more systematically approached within a pragma-dialectical framework. This is demonstrated for the argumentum and hominem, which is erroneously treated as a homogenous type of relevance fallacy in logico-centric analyses, so that cases where this is not justified must be treated as ad hoc exceptions. (shrink)

In a posthumous paper, Perelman discusses his decision to bring his theory of argumentation together with rhetoric rather than calling it an informal logic. This is due in part because of the centrality he gives to audience, and in part because of the negative attitude that informal logicians have to rhetoric. In this paper, I explore both of these concerns by way of considering what benefits Perelman’s work can have for informal logic, and what insights the work of informal logicians (...) might bring to the project of Perelman and Olbrechts-Tyteca. (shrink)

In addition to the distinction between species as a category and speciesas a taxon, the word species is ambiguous in a very different butequally important way, namely the temporal distinction between horizontal andvertical species. Although often found in the relevant literature, thisdistinction has thus far remained vague and undefined. In this paper the use ofthe distinction is explored, an attempt is made to clarify and define it, andthen the relation between the two dimensions and the implications of thatrelation are examined. (...) Using Darwin's analogy of language evolution forspeciesevolution, and by appealing to a major change in the conception of languagebetween 19th- and 20th-century linguistics, it is argued that the horizontaldimension has priority (pragmatic, epistemological, logical, and ontological)over the vertical dimension. This has immense ramifications for the modernspecies problem. Fundamentally, it favors horizontal species concepts oververtical ones. In so doing it places species realism on a much more securefoundation and largely undercuts species pluralism. In addition it raises aserious problem for the increasingly popular family of phylogenetic speciesconcepts, which generally suffer from a dimensionality confusion. However,thereis a recent trend within this family that attempts to restore the priority ofthe horizontal dimension. It is concluded that this trend should be affirmedandthat the species-as-individuals view should be abandoned. (shrink)

In this article I am concerned with analogical reasoning in ethics. There is no doubt that the use of analogy can be a powerful tool in our ethical reasoning. The importance of this mode of reasoning is therefore commonly accepted, but there is considerable debate concerning how its structure should be understood and how it should be assessed, both logically and epistemically. In this paper, I first explain the basic structure of arguments from analogy in ethics. I then discuss the (...) diversity of analogical arguments that can be found in ethics. I analyse their structure, assess them from a logical viewpoint, and show how they can be epistemically challenged and defended. The result of this investigation is that, contrary to a commonly held view, analogical reasoning can be a logically valid type of ethical reasoning that can provide reasons for action that are not worse than the reasons provided by any other kind of practical reasoning. (shrink)

Logic is the systematic study of patterns of correct inference. The first treatise on logic is Aristotle's Prior Analytics , written around 350 B.C. and there are remarkable similarities between the way he presented his theory of valid arguments and the way it is still taught today. He analyzes the form of various inferences and then illustrates them with concrete examples. He begins with very simple cases.

Correspondence analysis is Kooi and Tamminga’s universal approach which generates in one go sound and complete natural deduction systems with independent inference rules for tabular extensions of many-valued functionally incomplete logics. Originally, this method was applied to Asenjo–Priest’s paraconsistent logic of paradox LP. As a result, one has natural deduction systems for all the logics obtainable from the basic three-valued connectives of LP -language) by the addition of unary and binary connectives. Tamminga has also applied this technique to the paracomplete (...) analogue of LP, strong Kleene logic \. In this paper, we generalize these results for the negative fragments of LP and \, respectively. Thus, the method of correspondence analysis works for the logics which have the same negations as LP or \, but either have different conjunctions or disjunctions or even don’t have them as well at all. Besides, we show that correspondence analyses for the negative fragments of \ and LP, respectively, are also suitable without any changes for the negative fragments of Heyting’s logic \ and its dual \ and LP). (shrink)

Conceptual clarity is essential when engaging in dialogue to avoid unnecessary disagreement and to promote mutual understanding. In this issue devoted to clinical bioethics, the authors exemplify the virtue of careful conceptual analysis as they explore complex clinical questions regarding the essential nature of medicine, the boundaries of killing and letting die, the meaning of irreversibility in definitions of death, the argument for a right to try experimental medications, the ethical borders in complex medical billing, and the definition and modeling (...) of complex disease states. (shrink)

Abstract In his critique of modern libertarian thinking, Jeffrey Friedman (1997) argues that libertarian moral theory makes social science irrelevant. However, if its moral claims are hypothetical rather than categorical imperatives, then economics, history, sociology, and other disciplines play a central role in libertarian thought. Limitations on human knowledge necessitate abstractly formulated rules, among which are claims of rights. Further, Friedman's remarks on freedom rest on an erroneous understanding of the role of definitions in philosophy, and his characterization of the (...) ?right to do wrong? as a ?logical contradiction? reveals a misunderstanding of logic. (shrink)

Many philosophers subscribe to the view that philosophy is a priori and in the business of discovering necessary truths from the armchair. This paper sets out to empirically test this picture. If this were the case, we would expect to see this reflected in philosophical practice. In particular, we would expect philosophers to advance mostly deductive, rather than inductive, arguments. The paper shows that the percentage of philosophy articles advancing deductive arguments is higher than those advancing inductive arguments, which is (...) what we would expect from the vantage point of the armchair philosophy picture. The results also show, however, that the percentages of articles advancing deductive arguments and those advancing inductive arguments are converging over time and that the difference between inductive and deductive ratios is declining over time. This trend suggests that deductive arguments are gradually losing their status as the dominant form of argumentation in philosophy. (shrink)

Logicians disagree on (1) criteria for the presence of an argument, (2) criteria for adding implicit premises and (3) criteria for linking premises. I attempt to resolve all three problems, and in the process to remove the main obstacles to teaching diagramming. The first problem is resolved by working with real discourse that students find on their own, rather than the artificial examples and problems found in logic texts; it is further reduced by examining the different uses of argument and (...) understanding the extent to which the basic rules of diagramming are the same for the various uses. The other disagreements persist because logicians neglect to clarify the principal type of eakness we remedy by adding implicit premises and linking premises: in real discourse we do so to block substantive counterexamples, an idea correlated with that of substantive deduction, discussed by Govier, Wright and others. (shrink)

Jim Mackenzie; Authority, Journal of Philosophy of Education, Volume 22, Issue 1, 30 May 2006, Pages 57–65, https://doi.org/10.1111/j.1467-9752.1988.tb00177.x.

This essay presents a dialogical framework for treating philosophical disagreements as persuasion dialogues with analogical argumentation, with the aim of recasting philosophical disputes as disagreements over analogies. This has two benefits: it allows us to temporarily bypass conflicting metaphysical intuitions by focusing on paradigmatic examples, similarities, and the plausibility of conclusions for or against a given point of view; and it can reveal new avenues of argumentation regarding a given issue. This approach to philosophical disagreements is illustrated by studying the (...) role of argumentation by analogy in disputes over Lockean justifications of intellectual property rights, and disagreements over whether artificial agents should be treated as moral agents. Finally, a nonexhaustive list of possible global and local points of contention over analogical arguments is identified in order to highlight potential avenues of argumentation in disagreements over analogies. (shrink)

The modern belief that mindless forces can be ultimate efficient causes of natural events is a conceptual impossibility. The logically ultimate cause of any change, the something that is ultimately making it occur in the present moment, is either a mind or not. More specifically, the cause either chooses to act or it does not. By choice here, I mean an act of free will in the libertarian sense. Where there is choosing in this sense there must be a mind. (...) And when we say that an agent acts thus freely, we mean that it acts without being causally determined to act by anything beyond itself. However, this is conceptually indistinguishable from the idea of an ultimate efficient cause. To say that an agent is the ultimate cause in a causal chain is, by definition, to say that it acts without being caused to act by anything beyond itself. It is the head of the causal chain. It is, therefore, a matter of conceptual necessity that ultimate causes be minds, a fact that we have been blind to since the Scientific Revolution on the bad analogy of machines. Thus, every force ultimately governing the universe must be a mind corresponding either to the polytheist’s or the monotheist’s generic definition of divinity, and monotheism’s eternal mind will always be the most complete and justifiable explanation for the existence of the universe as a whole, even for the existence of the gods themselves. (shrink)

Three distinctly different interpretations of Aristotle’s notion of a sullogismos in Prior Analytics can be traced: (1) a valid or invalid premise-conclusion argument (2) a single, logically true conditional proposition and (3) a cogent argumentation or deduction. Remarkably the three interpretations hold similar notions about the logical relationships among the sullogismoi. This is most apparent in their conflating three processes that Aristotle especially distinguishes: completion (A4-6)reduction(A7) and analysis (A45). Interpretive problems result from not sufficiently recognizing Aristotle’s remarkable degree of metalogical (...) sophistication to distinguish logical syntax from semantics and, thus, also from not grasping him to refine the deduction system of his underlying logic. While it is obvious that Aristotle most often uses ‘sullogimos’ to denote a valid argument of a certain kind, we show that at Prior Analytics A4-6, 7, 45 Aristotle specifically treats a sullogismos as an elemental argument pattern having only valid instances and that such a pattern then serves as a rule of deduction in his syllogistic logic. By extracting Aristotle’s understanding of three proof-theoretic processes, this paper provides new insight into what Aristotle thinks reasoning syllogistically is and, moreover, it resolves three problems in the most recent interpretation that takes a sullogismos to be a deduction. (shrink)

A critical examination of the dialectical approach, focusing on a comparison ofthe illative and the dialectical definitions of argument. I distinguish a moderate, a strong and a hyper dialectical conception of argument. I critique Goldman's argument for the moderate conception and Johnson's argument for the strong conception, and argue that the moderate conception is correct.

By explaining the argument from ignorance in terms of the presumption of innocence, many textbooks in argumentation theory suggest that some arguments from ignorance might share essential features with some types of presumptive reasoning. The stronger version of this view, suggesting that arguments from ignorance and presumptive reasoning are almost indistinguishable, is occasionally proposed by Douglas Walton. This paper explores the nature and limits of the stronger proposal and argues that initial presumptions and arguments from ignorance are not closely connected. (...) There are three main reasons. First, the argument from ignorance, unlike typical presumptive reasoning, is a negative kind of inference. Second, the typical initial presumption is sensitive to a broader set of defeaters and thus assumes a higher standard of acceptability. Third, in dialectical terms, initial presumption and argument from ignorance bring different attacking rights and obligations. I conclude that Waltonian intuition is unsupported or, at best, is limited only to practical presumptions and practical arguments from ignorance. (shrink)

The article develops and justifies, on the basis of the epistemological argumentation theory, two central pieces of the theory of evaluative argumentation interpretation: 1. criteria for recognizing argument types and 2. rules for adding reasons to create ideal arguments. Ad 1: The criteria for identifying argument types are a selection of essential elements from the definitions of the respective argument types. Ad 2: After presenting the general principles for adding reasons (benevolence, authenticity, immanence, optimization), heuristics are proposed for finding missing (...) reasons, for deductive arguments, e.g., semantic tableaux are suggested. (shrink)

it is likely that there are many different social processes occurring in different parts of science and at different times, and that these processes will impact upon the nature, quality and quantity of the knowledge that is produced in a multitude of ways and to different extents. It seems clear to me that sometimes the social processes act to increase the reliability of knowledge (such as when there is a tradition of independently reproducing experiments) but sometimes does the opposite (when (...) a closed clique act to perpetuate itself by reducing opportunity for criticism). Simulation can perform a valuable role here by providing and refining possible linkages between the kinds of social processes and its results in terms of knowledge. Earlier simulations of this sort include Gilbert et al. in [10]. The simulation described herein aims to progress this work with a more structural and descriptive approach, that relates what is done by individuals and journals and what collectively results in terms of the overall process. (shrink)