INFORMAL LOGIC XlV. 1 , Winter 1992 Introduction RAJ_PH H. JOHNSON and J. ANTHONY BLAIR 1. Introduction We are pleased to publish this issue devoted to the work of Nicholas Rescher that has special significance for informal logic. Rescher's interest in informal logic is evidenced by his serving on this journal's Editorial Board, refereeing articles for it, and supporting it in other ways. What may be less well known is that some of his own philosophical work has a direct bearing on the problems addressed in this field. It has become customary to refer to the foundational significance for informal logic of Stephen Toulmin's The Uses of Argument (1958), Chaim Perelman and Lucy Olbrechts-Tyteca's The New Rhetoric (1958) and C. L. Hamblin's Fallacies (1970). In our view, Rescher's work in log- ic and argumentation theory in the 1970s needs to be recognized as having similar import for informal logic. Its influence has been felt on the thinking of a number of those developing theory in the field, for ex- ample John Woods and Douglas Walton. Elsewhere in this issue you will read of Rescher's contributions to argumentation theory and the theory of rationality. We de- vote the rest of this Introduction to some of Rescher's less well known contributions to informal logic-and to critical thinking. 2. Rescher and the Principle of Charity The idea of charity as a regulative prin- ciple of interpretation goes back to debates in the philosophy of language, and espe- cially to questions about the indeterminacy of radical translation. Quine cites N. L. Wilson's principle of charity, and offers his own "maxim of translation": "assertions startlingly false on the face of them are likely to turn on hidden differences of lan- guage" (Word and Object, 1960, p. 59). In his Introduction to Logic (1964) Rescher brought this principle to bear specifically on logic. He wrote: The governing rule in the reconstruction of enthymematic arguments is the principle of charity--onc should, insofar as is possible, try to make the argument valid and its premisses true. (p. 162) For Rescher here the principle is applied specifically to argument reconstruction, the reconstruction of (deductive) en thyme- mes, and the formulation of the unex- pressed premisses of such enthymemes. It is expressed in terms of the theory of eval- uation pegged to deductive logic: a good argument is a sound argument (having true premisses and being formally deductively valid). The principle of charity has, in sub- sequent formulations, been extended to ap- ply to the reconstruction of arguments generally-not just of their unexpressed premisses, but also of expressed textual material-to non-deductive as well as de- ductive arguments, and to the evaluation as well as the analysis of arguments. It has also been expressed in terms of broader theories of evaluation than the soundness model of good argument. While there is disagreement about the correct formulation of the principle of charity, most theorists today agree that some such principle plays an essential role in argument analysis and criticism at various levels. To our knowl- edge, Rescher was the first explicitly to 2 Johnson & Blair label and give a formulation to the principle of charity as it applies to argumentation. 3. Rescher on the nature of and models for argumentation How are we to conceive of the artifact we call argument and of the social activity of argumentation? These questions lie at the very core of the informal logic enter- prise. Under the influence of developments in the foundations of mathematics and for- mal logic in the late 19th century, the very notion of argument underwent a transfor- mation in logic. Essentially what hap- pened, we would say, is that the concept of argument was mathematicized. One of the earliest manifestations of the naturalization movement in philosophy was the reaction against this mathematici- zation of argumentation by such pioneer- ing authors as Perelman, Toulmin and Hamblin. We contend that Rescher be- longs in that number. His own particular contribution is most evident in two works: Plausible Reasoning (1976) and Dialec- tics: A Controversy Oriented Approach to the Theory of Knowledge (1977). In the former work, he formulates an account of appeals to authority in support of claims, which appeals do not fit the standard model of argument neatly, being neither premisses entailing their conclusions nor straightforward inductive evidence for them. In the latter work, Rescher reaches back to the scholastic tradition to investi- gate and revitalize the model of argument as a dialectical exchange between dispu- tants. In so doing he moves to counteract the solipsistic Cartesian model with an approach that emphasizes "the communal and controversy oriented aspects of ration- al argumentation and inquiry." Rescher's discussions of presumption and of the burden of proof in Dialectics alone justify a study of that work. Readers will find in this special issue papers on Rescher's work on plausible reasoning, inconsistency, fallacy and rationality-all central issues for informal logic. 4. Rescher's Sonoma presentation In a presentation titled, "Some Criti- cisms of Critical Thinking," given at the Second National Conference on Critical Thinking and Moral Critique at Sonoma State University in 1982, Rescher made a number of observations about informal logic and critical thinking, two of which have remained with us particularly. Here we are relying on our joint memory, as members of the audience that day: the ses- sion was not taped and to our knowledge Rescher's remarks were not published. (a) On two types of argument structure Rescher proposed that in analyzing ar- guments we should be attentive to two very different types of argument construction. Some arguments have a chain structure, and in them the argument is undercut by anyone flaw. ft is this type of argument that Meiland must have had in mind when he wrote (College Thinking, 1980, p. 34): Just as a chain is only as strong as its weak- est link so a conclusion is only as plausible as the weakest premises of an argument. But there is a different kind of argu- ment construction, which is like a rope made of different strands woven together. Here the premises do not function as indi- vidual links, but instead as overlapping, accumulating fibres. Such an argument will be as strong as the totality of its premises. It will not yield to the criticism that because the argument has a false premise, it is not sound. (b) On the epistemic orientation of critical thinking Elsewhere in "Some Criticisms" Rescher appealed to the pragmatists, par- ticularly William James, to help articulate Introduction 3 a concern he had about what might be called the cautious epistemic orientation of the critical thinking movement. He men- tioned James's view that there are two dif- ferent cogmtive orientations, ( I) seek truth, (2) avoid error, and quoted James's famous passage in Essays on Pragmatism: discouragement of cognitive risk-taking. Rescher expressed a worry that with the current emphasis, training in critical think- ing could well result in students who were error-avoiders rather than risk-takers in pursuit of truth. Our errors are surely not such awfully solemn things. In a world where we are so certain to incur them in spite of all our caution. a certain lightness of heart seems healthier than excessive nervousness on their behalf. Rescher said he thought there was too much concern in the critical thinking literature about the avoidance of error. While a concern to avoid error is cer- tainly legitimate, it has its downside: the 5. Conclusion Professor Rescher has left his imprint on everyone of the many areas to which he has pressed his singular talents and intel- lectual imagination. Informal logic and critical thinking are no exceptions, and these fields are the richer for his contributions-as the articles assembled in this issue make manifest. DIALOGUE Canadian Philosophical Review/Revue canadienne de philosophie e~l 1<1 revue trimc\trielle tic r A~sociation canadienne de philosophic. Des COIllril,,,t;orts repreo.;entant k~, domatnc:\ princ-ipaux de la y soot publiees. Certain;. des .Irtkles du volume 29 som mentivnnes j)i(//OgNt' i\ the quarterly jllurnall)fthe Canadian Philo,opnicaJ Association. Mos.1 of the main areas orphilo.'mphy are reprc'>cnted in II!', p;)O" by BRUCE BAUGH .. Le o.lalur Jc r