Erik C. W. Krabbe

The Problem of Retraction in Critical Discussion

In many contexts a retraction of commitment isfrowned upon. For instance, it is not appreciated,generally, if one withdraws a promise or denies anearlier statement. Critical discussion, too, caneasily be disrupted by retractions, if these occur toofrequently and at critical points. But on the otherhand, the very goal of critical discussion –resolution of a dispute – involves a retraction,either of doubt, or of some expressed point of view.A person who never retracts, not even under pressureof cogent arguments, would hardly qualify as areasonable discussant. Also, inconsistencies in onesposition, once they have been pointed out, must bedealt with by some kind of retraction. The problem ofretraction is to find a suitable model of dialoguethat allows retractions where they seem reasonable, oreven required, and rules them out (or puts sanctionsupon them) whenever they would become disruptive of awell-organized process of dialogue.The present paper tries to point to a solution basedon the following principles: (1) Retraction rulesdetermine what retractions are permissible, and (2) ifpermissible what the consequences of retraction are.(3) Retraction rules vary according to the type ofdialogue and (4) according to the type of commitmentretracted. For instance, assertions and mereconcessions need to be distinguished, as well aslight-side and dark-side commitments. (5) To accountfor our contradictory intuitions on the issue ofretractions, one may best resort to a complex type ofdialogue in which different retraction rules hold fordifferent parts.The paper explains, summarizes, and expands upon thediscussion of retraction in Commitment inDialogue by Douglas Walton and the present author(cf. Walton and Krabbe 1995).

Formal systems of dialogue rules

Section 1 contains a survey of options in constructing a formal system of dialogue rules. The distinction between material and formal systems is discussed (section 1.1). It is stressed that the material systems are, in several senses, formal as well. In section 1.2 variants as to language form (choices of logical constants and logical rules) are pointed out. Section 1.3 is concerned with options as to initial positions and the permissibility of attacks on elementary statements. The problem of ending a dialogue, and of infinite dialogues, is treated in section 1.4. Other options, e.g., as to the number of attacks allowed with respect to each statement, are listed in section 1.5. Section 1.6 explains the concept of a ‘chain of arguments’.From section 2 onward four types of dialectic systems are picked out for closer study: D, E, Di and Ei. After a preliminary section on dialogue sequents and winning strategies, the equivalence of derivability in intuitionistic logic and the existence of a winning strategy (for the Proponent) on the strength of Ei is shown by simple inductive proofs.Section 3 contains a — relatively quick — proof of the equivalence of the four systems. It follows that each of them yields intuitionistic logic.

So what? Profiles for relevance criticism in persuation dialogues

This paper discusses several types of relevance criticism within dialogue. Relevance criticism is a way one could or should criticize ones partners contribution in a conversation as being deficient in respect of conversational coherence. The first section tries to narrow down the scope of the subject to manageable proportions. Attention is given to the distinction between criticism of alleged fallacies within dialogue and such criticism as pertains to argumentative texts. Within dialogue one may distigguish tenability criticism, connection criticism, and narrow-type relevance criticism. Only the last of these three types of criticism constitutes a charge of fallacy and carries with it a burden of proof. In the second it is observed that a full study of narrow-type relevance criticism would require the construction of complicated, many-layered, dialogue systems. Such a study can, however, be profitably preceded by setting up profiles of dialogue that help us discuss the ins and outs of certain types of move. This is illustrated with an example.

Meeting in the House of Callias: Rhetoric and Dialectic

The purpose of this paper is to briefly describe and compare the original goals and perspectives of both rhetoric and dialectic in theory and in practice. Dialectic is the practice and theory of conversations; rhetoric that of speeches. For theory of dialectic, this paper will turn to Aristotles Topics and Sophistical Refutations; for theory of rhetoric, to his Rhetoric. Thus it will appear that rhetoric and dialectic are pretty close. Yet, on the other hand, there is a long tradition of mutual antagonism. The paper tries to summarize the common features of, as well as the differences between, the two. To get a taste of both dialectic and rhetoric in practice the reader is invited to enter the House of Callias, as we know it from Platos Protagoras. After this visit there remains no doubt that rhetoric and dialectic are intertwined on the level of practice. Moreover, we may look forward to their integration on the level of theory.

Argument and Multi-Agent Systems

Recent work in argumentation theory and informal (practical) logic has developed certain tools that seem to be useful and applicable to multi-agent systems in which participants need to interact. Multiple interacting agents that engage in persuasive dialogue, negotiation and the construction of joint plans of action have the potential to provide argumentation theory with a means to implement and evaluate their theories. In this chapter we address the issues that are of interest to argumentation and multi-agent systems, similarities between these interests, open problems on both sides, and avenues for future infra and interdisciplinary research.

Noncumulative Dialectical Models and Formal Dialectics

In [2] Barth and Krabbe advance a new philosophical motivation (intuitive interpretation) for Kripke’s semantics for constructive (intuitionistic) and minimal logic.’ Kripke intends the nodes (elements) H, H’ of a set K (of a model structure) to represent (possible) evidential situations of ourx2 Further, he suggests that we read HRH’ as follows: in situation H we may, as far as we know, advance to situation H’? In [2], on the other hand, the elements d, d’ of the set D (corresponding to Kripke’s K) in a dialectical structure represent possible dialectical situations of a specifiable dialectical subjectP and dRd’ is read accordingly. An evidential situation is characterized, at least partly, by the set of sentences verified or verifiable by us in that situation. Hence the “values” assigned to sentences (by a model) represent the predicates ‘%etified” and “not vented”.’ A dialectical situation is characterized, at least partly, by the set of sentences upon which positive agreement has been reached by a dialectical subject in that situation. Therefore the “values” assigned to sentences (by an interpretation/valuation) are these: A, for Agreement, N, for Non-agreemenk6

Arguments, Proofs, and Dialogues

To what extent do proofs fall within the scope of a theory of argumentation? In this paper I shall try to provide an answer. To this end, several types of proof need to be distinguished. Proofs of most types will be seen to be arguments, and therefore amenable to analysis from the point of view of argumentation studies. The last section presents a dialectical view of proof as an argument in dialogue that meets certain supplementary conditions. These conditions can, however, be formulated in dialectical terms.

Meeting in the House of Callias

The purpose of this paper is to briefly describe and compare the original goals and perspectives of both rhetoric and dialectic in theory and in practice. But, since this is an undertaking that would surely exceed the boundaries of any single paper, the best thing to do is to start at once with working definitions of rhetoric and of dialectic that will conveniently limit the subject. Hopefully, these limitations will not impair the paper’s further goal of contributing to a better appreciation of contemporary attempts to integrate rhetoric with dialectic.1

Who is Afraid of Figure of Speech

Aristotles illustrations of the fallacy of Figure of Speech (or Form of Expression) are none too convincing. They are tied to Aristotles theory of categories and to peculiarities of Greek grammar that fail to hold appeal for a contemporary readership. Yet, upon closer inspection, Figure of Speech shows many points of contact with views and problems that inhabit 20th-century analytical philosophy. In the paper, some Aristotelian examples will be analyzed to gain a better understanding of this fallacy. The case of the Third Man argument and some modern cases lend plausibility to the claim that Figure of Speech is of more interest as a type of fallacy than has generally been assumed. Finally, a case is made for the view that Figure of Speech, though listed among the fallacies dependent upon language, is not properly classified as a fallacy of ambiguity. More likely, it should be looked upon as a type of non sequitur. This has important consequences for the profile of dialogue associated with this fallacy.

Creative Reasoning in Formal Discussion

Systems of formal dialectics articulate methods of conflict resolution. To this end they provide norms to regulate verbal exchanges between the Proponent of a thesis and an Opponent. These regulated exchanges constitute what are known as formal discussions.One may ask what moves, if any, in formal discusions correspond to arguing for or against the thesis. It is claimed that certain moves of the Proponents are properly designated as arguing for the thesis, and that certain moves of the Opponent purport to criticize the tenability or the relevance of the reasons advanced. Thus the usefulness of formal dialectic systems as models for reasonable argument is vindicated.It is then proposed to make these systems more realistic by incorporating in them a norm of Creative Reasoning that removes the severe restrictions to which the Proponents arguing was hitherto subject. As a consequence, a certain type of irrelevant reason is no longer automatically excluded. Therefore, it is proposed to extend the Opponents rights to exert relevance criticism. The new dialectic systems are shown to be strategically equivalent to the original ones. Finally, it is stressed that the Opponents criticism should not be designated as arguing against the thesis. The Opponent criticizes, but does not argue.