It is argued in this study that (i) progress in the philosophy of mathematical practice requires a general positive account of informal proof; (ii) the best candidate is to think of informal proofs as arguments that depend on their matter as well as their logical form; (iii) articulating the dependency of informal inferences on their content requires a redefinition of logic as the general study of inferential actions; (iv) it is a decisive advantage of this conception of logic that it (...) accommodates the many mathematical proofs that include actions on objects other than propositions; (v) this conception of logic permits the articulation of project-sized tasks for the philosophy of mathematical practice, thereby supplying a partial characterisation of normal research in the field. (shrink)

Bayesian reasoning has been applied formally to statistical inference, machine learning and analysing scientific method. Here I apply it informally to more common forms of inference, namely natural language arguments. I analyse a variety of traditional fallacies, deductive, inductive and causal, and find more merit in them than is generally acknowledged. Bayesian principles provide a framework for understanding ordinary arguments which is well worth developing.

This paper is an exercise in intellectual history, an attempt to understand how a specific term—”informal logic”— came to be interpreted in so many different ways. I trace the emergence and development of “informal logic” to help explain the many different meanings, how they emerged and how they are related. This paper is also, to some degree, an account of a movement that developed outside the mainstream of philosophy, whose origins lie in a desire to make logic useful (echoing Dewey).

In this paper, we will explore two initiatives that focus on the importance of employing logical theories in educating people how to think and reason properly, one in Poland: The Lvov-Warsaw School; the other in North America: The Informal Logic Initiative. These two movements differ in the logical means and skills that they focus on. However, we believe that they share a common purpose: to educate students in logic and reasoning (logical education conceived as a process) so that they may (...) be able to apply their skills to analyze the issues in their society (logical culture as a result of logical education). The aim of the paper is to justify this claim by exploring research objectives and products that are common to both movements. (shrink)

In this paper, I propose that the inquiry known as a/the theory of argument is the “invention” of Trudy Govier, using that term in its rhetorical sense, viz., the process of choosing ideas appropriate to the subject. In her paper, “Is a Theory of Argument Possible?” Govier used the idea of theory of argument to focus her discussion on problems in argument analysis and evaluation that came to light in the 1970s and 1980s. The idea of a theory of argument (...) was already there but Govier “discovered” it in the sense that she made its potential clear. (shrink)

The paper outlines a conceptual framework for the critical assessment of argumentation which differs in some of its core characteristics from conventional approaches: it is resolutely semantic rather than formal in its method; it centers on obligations rather than beliefs; and its analytical focus is on the contingent necessity of conclusions, rather than on their persuasiveness or formal validity. The paper briefly illustrates the applications of this conceptual framework by reanalyzing a couple of examples taken from the argumentation analysis literature.

The title question and two subsequent questions are considered in the context of rational creativity. A-rational creativity is not considered.Q. Can creativity be taught?A. It depends on wh...

: In “What is a ‘Real’ Argument?” Geoff Goddu (2009) suggests and rejects four candidates for what a real argument is, concluding that argumentation theorists should abandon the idea that there is a theoretically significant sub-class of arguments that should be called real. In this paper, I argue against Goddu’s conclusion, finding that real arguments are arguments that are used or that have prospective use in the practice of thinking about matters that call for reasonable and reflective judgment concerning what (...) to believe or do. What makes these arguments theoretically distinct from arguments in general is that they are used or that they may be used in the pragmatic endeavor of attempting to establish good reasons for beliefs and actions. Real arguments are therefore the arguments that should be treated in a course that aims to improve the skills of argumentation that students might use outside of the classroom in real-life. (shrink)

Work on analogy has been done from a number of disciplinary perspectives throughout the history of Western thought. This work is a multidisciplinary guide to theorizing about analogy. It contains 1,406 references, primarily to journal articles and monographs, and primarily to English language material. classical through to contemporary sources are included. The work is classified into eight different sections (with a number of subsections). A brief introduction to each section is provided. Keywords and key expressions of importance to research on (...) analogy are discussed in the introductory material. Electronic resources for conducting research on analogy are listed as well. (shrink)

Identifying the missing or unstated premisses of arguments is important, because their logical quality depends on them. Textbook authors regard enthymematic syllogisms (e.g., "Elvis is a man, so Elvis is mortal") as having an unstated premiss - the major premiss (e.g., "All men are mortal"). They are said to be such because these syllogisms become formally valid when the major premiss is added (i.e., it is a gap-filler). I argue that unstated major premises are not gap-fillers: they support a part (...) of the argument that is already given implicitly - the inference claim ("If the premisses are true then the conclusion is true"). As such, their logical status is the same as that of an unstated proposition that supports the minor premiss, which is not part of the argument. Therefore, the so-called "major premiss" is not an unstated premiss of the enthymeme. (shrink)

Within the school of thought known as Critical Thinking, identifying or finding missing assumptions is viewed as one of the principal thinking skills. Within the new subject in schools and colleges, usually called Critical Thinking, the skill of finding missing assumptions is similarly prominent, as it is in that subject's public examinations. In this article we examine how school- and college-focused texts explain and teach ‘this very important skill’. The same texts also deal with the nature of assumptions, validity and (...) the role of stated reasons in arguments, and the way these matters are tackled will also be examined in our inquiry. In addition we explore what respected contributors to the critical thinking movement have had to say about some of these issues. (shrink)

The concept of an 'assumption' is discussed, and it is suggested that the psychological model implied by normal usage is misleading. A new model is proposed which distinguishes between 'assumptions', as constraints upon the thinking process, and 'postulates', as corresponding potential or actual propositional vocalizations. Some evidence for this model is provided, and its implications, particularly for the process of assumption identification, are discussed. It is suggested that assumption identification requires lateral thinking, and needs to be separated from problem-solving. The (...) discussion is offered as an instance of an appropriate type of fusion of psychological and informal-logical approaches. (shrink)

This is a critical examination of Antoine Arnauld's Logic or the Art of Thinking (1662), commonly known as the Port-Royal Logic. Rather than reading this work from the viewpoint of post-Fregean formal logic or the viewpoint of seventeenth-century intellectual history, I approach it with the aim of exploring its relationship to that contemporary field which may be labeled informal logic and/or argumentation theory. It turns out that the Port-Royal Logic is a precursor of this current field, or conversely, that this (...) field may be said to be in the same tradition. (shrink)

David N. Perkins has studied everyday reasoning by an experimental-critical approach involving taped interviews during which subjects reflect on controversial issues and articulate their reasoning on both sides. The present author has studied scientific reasoning in natural language by an historical-textual approach involving the reconstruction and evaluation of the arguments in Galileo's Two Chief World Systems. They have, independently, reached the strikingly similar substantive conclusion that the most common flaw of informal reasoning is the failure to consider lines of argument (...) supporting conclusions contrary to the one in fact reached. This article describes, compares, and contrasts their respective approaches, results, and theoretical frameworks. (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.

A popular three-stage argument appraisal strategy calls for (1) identifying the parts of the argument, (2) classifYing the argument as deductive, inductive, or some other type, and (3) appraising the argument using the standards appropriate for the type. This strategy fails for a number of reasons. I propose a comprehensive alternative approach that distinguishes between inductive, deductive, and other standards; calls for the successive application of standards combined with assumption-ascription, according to policies that depend for their selection on the goals (...) of the appraiser; and provides for qualified reasoning. (shrink)

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 this paper, I assume, perhaps controversially, that translation into a language of formal logic is not the method by which mathematicians assess mathematical reasoning. Instead, I argue that the actual practice of analyzing, evaluating and critiquing mathematical reasoning resembles, and perhaps equates with, the practice of informal logic or argumentation theory. It doesn’t matter whether the reasoning is a full-fledged mathematical proof or merely some non-deductive mathematical justification: in either case, the methodology of assessment overlaps to a large extent (...) with argument assessment in non-mathematical contexts. I demonstrate this claim by considering the assessment of axiomatic or deductive proofs, probabilistic evidence, computer-aided proofs, and the acceptance of axioms. I also consider Jody Azzouni’s ‘derivation indicator’ view of proofs because it places derivations—which may be thought to invoke formal logic—at the center of mathematical justificatory practice. However, when the notion of ‘derivation’ at work in Azzouni’s view is clarified, it is seen to accord with, rather than to count against, the informal logical view I support. Finally, I pose several open questions for the development of a theory of mathematical argument. (shrink)

This volume presents a selection of papers reflecting key theoretical issues in argumentation theory. Its six sections are devoted to specific themes, including the analysis and evaluation of argumentation, argument schemes and the contextual embedding of argumentation. The section on general perspectives on argumentation discusses the trends of empiricalization, contextualization and formalization, offers descriptions of the analytical and evaluative tools of informal logic, and highlights selected principles that argumentation theorists do and do not agree upon. In turn, the section on (...) linguistic approaches to argumentation focuses on the problem of distinguishing between explanation and argument, while also elaborating on the role of verbal indicators of argument schemes. All essays included in this volume point out notable recent developments in the study of argumentation. (shrink)

This volume presents mathematical game theory as an interface between logic and philosophy.

In Coalescent Argumentation, Michael Gilbert criticizes the "Critical-Logical Model" which he claims focuses on truth and treats arguments a-contextually; he proposes an alternative theory of coalescent argumentation which focuses on cont ent and consensus. I shall examine the dispute between the C-L and the coalescent models using the coalescent approach, thereby attempting to find which points of contention are real disagreements and which are only peripheral or apparent. Finally, I sh all examine the extent to which this examination, undertaken using (...) the coalescent model, differs from what would have been done using a C-L model. (shrink)

Woods and Walton deserve credit for including a discussion of “economic reasoning” and its susceptibility to the “fallacy of composition.” Unfortunately, they did not sufficiently pursue the topic, and argumentation scholars have apparently ignored their pioneering effort. Yet, obviously, economic argumentation is extremely important, and economists constantly harp on this fallacy. This paper calls attention to this problem, elaborating my own approach, which is empirical, historical, and meta-argumentational.

This paper examines the views of Fogelin, Woods, Johnstone, etc., concerning deep disa-greements, force-five standoffs, philosophical controversies, etc. My approach is to reconstruct their views and critiques of them as meta-arguments, and to elaborate the meta-argumentative aspects of radical disa-greements. It turns out that deep disagreements are resolvable to a greater degree than usually thought, but only by using special principles and practices, such as meta-argumentation, ad hominem argumentation, Ramsey’s principle, etc.

Mathematicians often speak of conjectures, yet unproved, as probable or well-confirmed by evidence. The Riemann Hypothesis, for example, is widely believed to be almost certainly true. There seems no initial reason to distinguish such probability from the same notion in empirical science. Yet it is hard to see how there could be probabilistic relations between the necessary truths of pure mathematics. The existence of such logical relations, short of certainty, is defended using the theory of logical probability (or objective Bayesianism (...) or non-deductive logic), and some detailed examples of its use in mathematics surveyed. Examples of inductive reasoning in experimental mathematics are given and it is argued that the problem of induction is best appreciated in the mathematical case. (shrink)

This essay addresses the collapse/incoherence problem for normative frameworks that contain both fundamental values and rules for promoting those values. The problem is that in some cases, we would bring about more of the fundamental value by violating the framework’s rules than by following them. In such cases, if the framework requires us to follow the rules anyway, then it appears to be incoherent; but if it allows us to make exceptions to the rules, then the framework “collapses” into one (...) that doesn’t make use of rules in the first place. The chapter begins with an examination of happiness and truth as fundamental values in Mill’s work, which lead into parallel versions of the collapse/incoherence problem in ethics and epistemology. It then sets out the collapse problem for rule-consequentialist approaches in ethics, truth-directed accounts of justification in epistemology, and epistemological approaches to argument cogency. The chapter closes with discussion of two potential solutions to the problem. (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)

Analyzing argumentative discourse is not a an activity exclusively reserved for scholars in argumentation theory, rhetoric, and philosophy of language. This paper proposes that the faculty of analyzing argument structure is a basic precondition of und erstanding one another in argumentational interactions. Based on an examination of televised debates, it is demonstrated how participants employ quasi-logical schemata to reconstruct implicit elements in other participants's argument structures for purpo ses of clarification and criticism. This very descriptive approach entrusts, as it were, (...) the actual argument analysis to the language users themselves. (shrink)

Why are enthymemes so frequent? Are we dumb arguers, smart rhetoricians, or parsimonious reasoners? This paper investigates systematic use of enthymemes, criticizing the application of the principle of charity to their interpretation. In contrast, I propose to analyze enthymematic argumentation in terms of parsimony, i.e. as a manifestation of the rational tendency to economize over scant resources. Consequences of this view on the current debate on enthymemes and on their rational reconstruction are discussed.

Although Hume’s critique of the design argument is a powerful non-inductive meta-argument, the main line of critical reasoning is not analogical but rather a complex meta-argument. It consists of two parts, one interpretive, the other evaluative. The critical meta-argument advances twelve criticisms: that the design argument is weak because two of its three premises are justified by inadequate subarguments; because its main inference embodies four flaws; and because the conclusion is in itself problematic for four reasons. Such complexity is quite (...) manageable in a meta-argumentation approach. (shrink)

This paper examines whether philosophers of argument, in spite of their disavowing ‘timeless principles’, nevertheless embrace a set of principles, or axioms, to underlie argumentation theory. First, it reviews the thinking of some prominent philosophers of argument; second, it extracts some principles common to their philosophies; and third, it draws out possible consequences for argumentation theory and asks whether such theory has an underlying political posture.

Knowledge is one of the most important factors determining the development of global economy and overcoming the present existing inequalities. Humankind needs a fair distribution of the potential of knowledge because its big social problems and difficulties today are due to the existence of deep‐going differences in its possession and use. This paper is an attempt to analyze and present certain philosophical arguments and conceptions justifying cooperative decision‐making in the searching for fair distribution of the benefits of knowledge in the (...) globalized world. Made individually or collectively, these decisions do not worsen the status of anyone ‐ rather they can lead to the use of benefits of knowledge in the interest of all people. A fair distribution of resources and achievements of a knowledge‐based economy is of key importance for the future of humankind. There exist three significant roads to justification of cooperative decisionmaking in a global aspect. The main problem here is that of how to ensure equal access of all members of the global society to benefits of knowledge.In this paper are considered communitarianism, J. Habermas` theory of communicative action and public choice theories. The right to participate in activities of the knowledge society and to share in its wealth is related to the use of social and economic benefits. A distributive justice, including such right, could be based on communitarian political and moral values and principles. Any violation of such principles means existence of social injustice, with lasting consequences, including loss of access to natural goods, such as food and water. (shrink)

The paper argues that argument and argumentation deserve philosophical attention but do not receive it, and proposes some explanations. It then asks whether there is a field of philosophy, “philosophy of argument,” that might attract philosophers’ attention. A case is made that such a field exists. However, challenges to that case seriously undermine it. Thus those who want philosophers to pay more attention to argument must find other ways to make their case.

Chapter 2 of Mill’s On Liberty is reconstructed as a complex argument for freedom of discussion; it consists of three subarguments, each possessing illative and dialectical components. The illative component is this: freedom of discussion is desirable because it enables us to determine whether an opinion is true, whereas its denial amounts to an assumption of infallibility; it improves our understanding and appreciation of the supporting reasons of true opinions, and our understanding and appreciation of their practical or emotional meaning; (...) it enables us to understand and appreciate every side of the truth, given that opinions tend to be partly true and partly false and people tend to be one-sided. The dialectical component consists of replies to ten objections, five in the first subargument, three in the second, one in the third, and one general. An analysis of Mill’s argument suggests that it is a contribution to argumentation theory; it advocates and practices a dialectical approach; its reconstruction and analysis are a contribution to argumentation theory; and it raises in a striking manner the issue of the relationship between epistemology and argumentation theory. (shrink)

I discuss eight theses espoused or occasioned by Toulmin: The validity standard is nearly always the wrong standard for real-life reasoning. Little in good reasoning is topic neutral. The probability calculus distorts much probabilistic reasoning. Scant resources have a benign influence on human reasoning. Theoretical progress and conceptual change are connected. Logic should investigate the cognitive aspects of reasoning and arguing. Ideal models are unsuitable for normativity. The role of the Can Do Principle.

The argument diagramming method developed by Monroe C. Beardsley in his (1950) book Practical Logic, which has since become the gold standard for diagramming arguments in informal logic, makes it possible to map the relation between premises and conclusions of a chain of reasoning in relatively complex ways. The method has since been adapted and developed in a number of directions by many contemporary informal logicians and argumentation theorists. It has proved useful in practical applications and especially pedagogically in teaching (...) basic logic and critical reasoning skills at all levels of scientific education. I propose in this essay to build on Beardsley diagramming techniques to refine and supplement their structural tools for visualizing logical relationships in a number of categories not originally accommodated by Beardsley diagramming, including circular reasoning, reductio ad absurdum arguments, and efforts to dispute and contradict arguments, with applications and analysis. (shrink)