Evaluating Arguments Based on Toulmin’s Scheme

Toulmin’s scheme for the layout of arguments (1958, The Uses of Argument, Cambridge University Press, Cambridge) represents an influential tool for the analysis of arguments. The scheme enriches the traditional premises-conclusion model of arguments by distinguishing additional elements, like warrant, backing and rebuttal. The present paper contains a formal elaboration of Toulmin’s scheme, and extends it with a treatment of the formal evaluation of Toulmin-style arguments, which Toulmin did not discuss at all. Arguments are evaluated in terms of a so-called dialectical interpretation of their assumptions. In such an interpretation, an argument’s assumptions can be evaluated as defeated, e.g., when there is a defeating reason against the assumption. The present work builds on recent research on defeasible argumentation (cf. e.g. the work of Pollock, Reiter, Loui, Vreeswijk, Prakken, Hage and Dung). More specifically, the author’s work on the dialectical logic DEFLOG and the argumentation tool ARGUMED serve as starting points.     

Argumentation Without Arguments

A well-known ambiguity in the term ‘argument’ is that of argument as an inferential structure and argument as a kind of dialogue. In the first sense, an argument is a structure with a conclusion supported by one or more grounds, which may or may not be supported by further grounds. Rules for the construction and criteria for the quality of arguments in this sense are a matter of logic. In the second sense, arguments have been studied as a form of dialogical interaction, in which human or artificial agents aim to resolve a conflict of opinion by verbal means. Rules for conducting such dialogues and criteria for their quality are part of dialogue theory. Usually, formal accounts of argumentation dialogues in logic and artificial intelligence presuppose an argument-based logic. That is, the ways in which dialogue participants support and attack claims are modelled as the construction of explicit arguments and counterarguments (in the inferential sense). However, in this paper formal models of argumentation dialogues are discussed that do not presuppose arguments as inferential structures. The motivation for such models is that there are forms of inference that are not most naturally cast in the form of arguments (such as abduction, statistical reasoning and coherence-based reasoning) but that can still be the subject of argumentative dialogue. Some recent work in artificial intelligence is discussed which embeds non-argumentative inference in an argumentative dialogue system, and some general observations are drawn from this discussion.     

From Figure to Argument: <Emphasis Type="Italic">Contrarium</Emphasis> in Roman Rhetoric

In Roman rhetoric, contrarium was variably considered either a figure of speech or an argument. The paper examines the logical pattern of this type of argument, which according to Cicero is based on a third Stoic indemonstrable syllogism: The persuasiveness of this type of argument, however, vitally depends on the validity of the alleged ‹incompatibility’ forming its major premiss. Yet this appears to be the argument’s weak point, as the ‹incompatibilities’ employed generally hold for the most part only, and are reducible to topical argument schemes. This is why in practical usage such arguments are most often phrased as rhetorical questions, the persuasive force of which, enhanced by certain strategical maneuverings and fallacies, makes the audience swallow the argument.     

The Value of Topoi

Despite Vancil’s (1979) proclamation over twenty years ago that topoi have been abandoned in argument theory, this essay contends that topoi should have a vital role in contemporary argumentation theory. Four key areas are identified where topoi are (or can be) essential tools for argumentation: Locating argument, building argument, development of critical thinking, and argument pedagogy. As a result, teachers and students of argument can both benefit from a (re)discovery of topoi.     

The Sunk Costs Fallacy or Argument from Waste

This project tackles the problem of analyzing a specific form of reasoning called sunk costs in economics and argument from waste in argumentation theory. The project is to build a normative structure representing the form of the argument, and then to apply this normative structure to actual cases in which the sunk costs argument has been used. The method is partly structural and partly empirical. The empirical part is carried out through the analysis of case studies of the sunk costs argument found in business decision-making, as well as other areas like medical decision-making and everyday conversational argumentation. The structural part is carried out by using existing methods and techniques from argumentation theory, like argumentation schemes. The project has three especially significant findings. First, the sunk costs argument is not always fallacious, and in many cases it can be seen to be a rational precommitment strategy. Second, a formal model of argumentation, called practical reasoning, can be constructed that helps a rational critic to judge which sunk costs arguments are fallacious and which are not. Third, this formal model represents an alternative model of rationality to the cost-benefit model based on Bayesian calculation of probabilities. This alternative model is called the argumentation model, and it is based on interpersonal reasoning in dialogue as the model of rational thinking. This model in turn is based on the underlying notion of commitment in dialogue.     

Arguments,Meta-arguments,and Metadialogues: A Reconstruction of Krabbe,Govier, and Woods

Krabbe (2003, in F.H. van Eemeren, J.A. Blair, C.A. Willard and A.F. Snoeck Henkemans (eds.), Proceedings of the Fifth Conference of the International Society for the Study of Argumentation, Sic Sat, Amsterdam, pp. 641–644) defined a metadialogue as a dialogue about one or more dialogues, and a ground-level dialogue as a dialogue that is not a metadialogue. Similarly, I define a meta-argument as an argument about one or more arguments, and a ground-level argument as one which is not a meta-argument. Krabbe (1995, in F.H van Eemeren, R. Grootendorst, J.A. Blair, C.A. Willard and A.F. Snoeck Henkemans (eds.), Proceedings of the Third ISSA Conference on Argumentation, Sic Sat, Amsterdam, pp. 333–344) showed that formal-fallacy criticism (and more generally, fallacy criticism) consists of metadialogues, and that such metadialogues can be profiled in ways that lead to their proper termination or resolution. I reconstruct Krabbe’s metadialogical account into monolectical, meta-argumentative terminology by describing three-types of meta-arguments corresponding to the three ways of proving formal invalidity he studied: the trivial logic-indifferent method; the method of counterexample situation; and the method of formal paraphrase. A fourth type of meta-argument corresponds to what Oliver (1967, Mind 76, 463–478), Govier (1985, Informal Logic 7, 27–33), and Copi (1986) call refutation by logical analogy. A fifth type of meta-argument represents my reconstruction of arguments by parity of reasoning studied by Woods and Hudak (1989, Informal Logic 11, 125–139). Other particular meta-arguments deserving future study are Hume’s critique of the argument from design in the Dialogues Concerning Natural Religion, and Mill’s initial argument in The Subjection of Women about the importance of established custom and general feeling vis-à-vis argumentation.     

Goodman’s “New Riddle”

First, a brief historical trace of the developments in confirmation theory leading up to Goodman’s infamous “grue” paradox is presented. Then, Goodman’s argument is analyzed from both Hempelian and Bayesian perspectives. A guiding analogy is drawn between certain arguments against classical deductive logic, and Goodman’s “grue” argument against classical inductive logic. The upshot of this analogy is that the “New Riddle” is not as vexing as many commentators have claimed (especially, from a Bayesian inductive-logical point of view). Specifically, the analogy reveals an intimate connection between Goodman’s problem, and the “problem of old evidence”. Several other novel aspects of Goodman’s argument are also discussed (mainly, from a Bayesian perspective).     

Evaluating the Meta-Slope: Is there a Slippery Slope Argument against Slippery Slope Arguments?

Slippery slope arguments (SSAs) have often been viewed as inherently weak arguments, to be classified together with traditional fallacies of reasoning and argumentation such as circular arguments and arguments from ignorance. Over the last two decades several philosophers have taken a kinder view, often providing historical examples of the kind of gradual change on which slippery slope arguments rely. Against this background, Enoch (2001, Oxford Journal of Legal Studies 21(4), 629–647) presented a novel argument against SSA use that itself invokes a slippery slope. Specifically, he argued that the very reasons that can make SSAs strong arguments mean that we should be poor at abiding by the distinction between good and bad SSAs, making SSAs inherently undesirable. We argue that Enoch’s meta-level SSA fails on both conceptual and empirical grounds.     

Rawls and Research on Cognitively Impaired Patients: A Reply to Maio

In his paper, “The Relevance of Rawls’ Principle of Justice for Research on Cognitively Impaired Patients” (Theoretical Medicine and Bioethics 23 (2002):45–53), Giovanni Maio has developed athought-provoking argument for the permissibility of non-therapeutic research on cognitively impaired patients. Maio argues that his conclusion follows from the acceptance of John Rawls’s principles of justice, specifically, Rawls’s “liberty principle” Maio has misinterpreted Rawls’s “libertyprinciple” – correctly interpreted it does notsupport non-therapeutic research on cognitivelyimpaired patients. Three other ‘Rawlsian’ arguments are suggested by Maio’s discussion –two “self-respect” arguments and a “presumed consent” argument – but none of them are convincing. However, an alternative argument developed from Rawls’s discussion of “justice in health care” in his most recent book, Justice as Fairness: A Restatement, may justify certain kinds of non-therapeutic research on some cognitively impaired patients in special circumstances. We should not expect anything more permissive from a liberal theory of justice. This revised version was published online in June 2006 with corrections to the Cover Date.     

Discussions Quinton’s Neglected Argument for Scientific Realism

Summary  This paper discusses an argument for scientific realism put forward by Anthony Quinton in The Nature of Things. The argument – here called the controlled continuity argument – seems to have received no attention in the literature, apparently because it may easily be mistaken for a better-known argument, Grover Maxwell’s “argument from the continuum”. It is argued here that, in point of fact, the two are quite distinct and that Quinton’s argument has several advantages over Maxwell’s. The controlled continuity argument is also compared to Ian Hacking’s “argument from coincidence”. It is pointed out that both arguments are to a large extent independent from considerations about high-level scientific theories, and that both are abductive arguments at the core. But these similarities do not dilute an important difference related to the fact that Quinton’s argument cleverly seeks to anchor belief in unobservable entities in realism about ordinary objects, which is a position shared by most contemporary scientific anti-realists.     

The computational value of debate in defeasible reasoning

Defeasible reasoning is concerned with the logics of non-deductive argument. As is described in the literature, the study of this type of reasoning is considerably more involved than the study of deductive argument, even so that, in realistic applications, there is often a lack of resources to perform an exhaustive analysis. It follows that, in a theory of defeasible reasoning, the order and direction in which arguments are developed, i.e. theprocedure, is important. The aim of this article is to show that debate is the most efficient procedure to argue in the presence of limited resources. To do so, there is first some general theory on defeasible argumentation, which is followed by an introduction to the problem of dialectical search. The problem of dialectical search is (or at least, should be) the essential issue in every theory on argumentation, and emerges at every occasion that involves adjudication on competing arguments. Starting with an example, it is explained that dialectical search can be best scheduled according to classical debating techniques, that work along well-tried methods. These methods (which include various forms of curtailment, interruption, and interpretation) have proven their value in keeping debating efforts within reasonable bounds. How they apply in a theory of formal argument, will be shown in this article.This research was made possible by SION, and is financed by NWO under contract number 612-316-019. Part of this research has been conducted at the Vrije Universiteit Amsterdam. This article contains fragments of Chapter 6 and Chapter 7 of the author's dissertation. Studies in Defeasible Argumentation (1993).     

Meaning Approached Via Proofs

According to a main idea of Gentzen the meanings of the logical constants are reflected by the introduction rules in his system of natural deduction. This idea is here understood as saying roughly that a closed argument ending with an introduction is valid provided that its immediate subarguments are valid and that other closed arguments are justified to the extent that they can be brought to introduction form. One main part of the paper is devoted to the exact development of this notion. Another main part of the paper is concerned with a modification of this notion as it occurs in Michael Dummett’s book The Logical Basis of Metaphysics. The two notions are compared and there is a discussion of how they fare as a foundation for a theory of meaning. It is noted that Dummett’s notion has a simpler structure, but it is argued that it is less appropriate for the foundation of a theory of meaning, because the possession of a valid argument for a sentence in Dummett’s sense is not enough to be warranted to assert the sentence.     

The Aggressiveness of Playful Arguments

Some people report that they argue for play. We question whether and how often such arguments are mutually entertaining for both participants. Play is a frame for arguing, and the framing may not always be successful in laminating the eristic nature of interpersonal argumentation. Previous research and theory suggest that playfulness may be associated with aggression. Respondents (N = 199) supplied self-report data on their arguing behaviors and orientations. We found support for the hypothesis that self-reported playfulness and aggression are directly associated. We found less evidence for our hypothesized inverse association between self-reported playfulness and indices of cooperation and avoidance. Self-reports of playfulness are not significantly associated with expert coders’ ratings of either playfulness or aggressiveness. The claim that an argument is playful should be met with skepticism, although playful arguments are possible.     

Conscience: Aquinas — With a hint of aristotle

The paper presents Aquinas’s account of conscience, and argues that key elements of this account are key elements too of Aristotle’s moral theory. The paper’s purpose is to encourage debate over conscience as not only a Stoic/Christian concept but one with deeper— and more widespread—roots in western ethical tradition.     

What is a Sophistical Refutation?

From Aristotle’s Sophistical Refutations the following classifications are put forward and defended through extensive excerpts from the text. (AR-PFC) All sophistical refutations are exclusively either ‘apparent refutations’ or ‘proofs of false conclusions’. (AR-F) ‘Apparent refutations’ and ‘fallacies’ name the same thing. (ID-ED) All fallacies are exclusively either fallacies in dictione or fallacies extra dictionem. (ID-nAMB) Not all fallacies in dictione are due to ambiguity. (AMB-nID) Not all fallacies due to ambiguity are fallacies in dictione. (AMB&ID-ME) The set of fallacies due to ambiguity and fallacies in dictione together comprise the set of arguments said to be “dependent on mere expression”. Being “dependent on mere expression” and “dependent on language” are not the same (instances of the latter form a proper subset of instances of the former). (nME-FACT) All arguments that are not against the expression are “against the fact.” (FACT-ED) All fallacious arguments against the fact are fallacies extra dictionem (it is unclear whether the converse is true). (MAN-ARG) The solutions of fallacious arguments are exclusively either “against the man” or “against the argument.” (10) (F-ARG) Each (type of) fallacy has a unique solution (namely, the opposite of whatever causes the fallacy), but each fallacious argument does not. However, each fallacious argument does have a unique solution against the argument, called the ‘true solution’ (in other words, what fallacy a fallacious argument commits is determined by how it is solved. However, if the solution is ‘against the man’ then this is not, properly speaking, the fallacy committed in the argument. It is only the ‘true solution’—the solution against the argument, of which there is always only one—that determines the fallacy actually committed).     

The ‘Gray’s Elegy’ Argument, and The Prospects for the Theory of Denoting Concepts

Russell’s new theory of denoting phrases introduced in “On Denoting” in Mind 1905 is now a paradigm of analytic philosophy. The main argument for Russell’s new theory is the so-called ‘Gray’s Elegy’ argument, which purports to show that the theory of denoting concepts (analogous to Frege’s theory of senses) promoted by Russell in the 1903 Principles of Mathematics is incoherent. The ‘Gray’s Elegy’ argument rests on the premise that if a denoting concept occurs in a proposition, then the proposition is not about the concept. I argue that the premise is false. The ‘Gray’s Elegy’ argument does not exhaust Russell’s ammunition against the theory of denoting concepts. Another reason Russell rejects the theory is, as he says, that it cannot provide an adequate account of non-uniquely denoting concepts. In the last section of the paper, I argue that even though Russell was right in thinking that the theory of denoting concepts cannot provide an adequate account of non-uniquely denoting concepts, Russell’s new theory does not succeed in eliminating the occurrence of all denoting concepts, as it requires a commitment to the existence of variables that indirectly denote their values. However, the view that variables are denoting concepts is unproblematic once the ‘Gray’s Elegy’ argument is blocked.     

Reflective Argumentation: A Cognitive Function of Arguing

Why do we formulate arguments? Usually, things such as persuading opponents, finding consensus, and justifying knowledge are listed as functions of arguments. But arguments can also be used to stimulate reflection on one’s own reasoning. Since this cognitive function of arguments should be important to improve the quality of people’s arguments and reasoning, for learning processes, for coping with “wicked problems,” and for the resolution of conflicts, it deserves to be studied in its own right. This contribution develops first steps towards a theory of reflective argumentation. It provides a definition of reflective argumentation, justifies its importance, delineates it from other cognitive functions of argumentation in a new classification of argument functions, and it discusses how reflection on one’s own reasoning can be stimulated by arguments.     

What could be caused must actually be caused

I give two arguments for the claim that all events which occur at the actual world and are such that they could be caused, are also such that they must actually be caused. The first argument is an improvement of a similar argument advanced by Alexander Pruss, which I show to be invalid. It uses Pruss’s Brouwer Analog for counterfactual logic, and, as a consequence, implies inconsistency with Lewis’s semantics for counterfactuals. While (I suggest) this consequence may not be objectionable, the argument founders on the fact that Pruss’s Brouwer Analog has a clear counterexample. I thus turn to a second, “Lewisian” argument, which requires only an affirmation of one element of Lewis’s analysis of causation and one other, fairly weak possibility claim about the nature of wholly contingent events. The final section of the paper explains how both arguments escape objections from supposed indeterminacy in quantum physics.     

The Argumentative Structure of Persuasive Definitions

In this paper we present an analysis of persuasive definition based on argumentation schemes. Using the medieval notion of differentia and the traditional approach to topics, we explain the persuasiveness of emotive terms in persuasive definitions by applying the argumentation schemes for argument from classification and argument from values. Persuasive definitions, we hold, are persuasive because their goal is to modify the emotive meaning denotation of a persuasive term in a way that contains an implicit argument from values. However, our theory is different from Stevenson’s, a positivistic view that sees emotive meaning as subjective, and defines it as a behavioral effect. Our proposal is to treat the persuasiveness produced by the use of emotive words and persuasive definitions as due to implicit arguments that an interlocutor may not be aware of. We use congruence theory to provide the linguistic framework for connecting a term with the function it is supposed to play in a text. Our account allows us to distinguish between conflicts of values and conflicts of classifications.