5 PUZZLE FOR ANALYSIS: FIND THE FALLACY A major stumbling block to the effective use of the informal fallacies in the teaching of practical logic is the lack of adequate and applicable theory to tell us, even in what are presumed to be paradigm cases, whether or not a given inference really is invalid (incorrect, fallacious). In the task of working toward a better theoretical and practical understanding of the fallacies one is often confronted with various interesting cases of "fallacy overlap", where an argument that we would probably want to classify as fallacious sits on a not very well defined fence between two of the traditional major informal fallacies. Hamblin (1, p. 34) notes that some standard examples that are usually cited as instances of the petitio could be equally well classified as cases of the ad verecundiam. Some of these borderline cases are strikingly suggestive as to the more or less exact logic of the fallacies. It is one of these significant examples of quite general interest that we would like to propose as a puzzle for analysis. Here is an argument apparently redolent of "circular reasoning". The residents of an outlying suburb take forward a plebiscite to City Hall in favour of improving the bus service in their neighbourhood. City Hall replies: "Why should we add more buses when the ones currently assigned to that route are operating at a deficit because not enough people are using them?" The residents then point out that if more buses were scheduled at a greater variety of times, and the residents became accustomed to being able to rely on regular, reliable bus service at times that would be convenient to them, then the service would be more fully used. They suggest that it is for the very reason that the present service is so poor that nobody takes the bus. Nobody takes the bus because the present service is poor! City Hall's argument that the present service should remain at its present level because few people now use the existing service is one that in effect traps the residents in a vicious circle. The dialectical manoeuvre is a familiar enough one in the political forum. An existing poor service or underused but inefficient amenity can always, in just this quite characteristic way, be cited as "evidence" contra its own improvement. The form the argument takes can be formulated dialectically as follows. Opponent: Service S is underused, therefore it should remain at its present level. Respondent: Service S is underused because it remains at its present level. Notice that the opponent argues from the premiss'S is underused' to a conclusion that posits S remaining at the present level. The respondent argues the other way around. Hence the impression of circularity. Two other complicating elements are present however. The respondent's inference is explicitly causal. And one feels that what is at stake is a causal cycle. Second, the opponent's inference seems to be more explicitly normative, containing as it does th~ word 'should'. < I 6 Why a causal cycle seems to be involved is evident from the perspective of the citizens in our example. Given City Hall's proclivity for statistics, it is true to say that the present service is so poor because nobody takes the bus. But nobody takes the bus precisely because the present service is so' poor. We are on a causal carousel of conservatism. The essential fallaciousness of this sort of argument would thus seem to be a curious hy~ri~ of post hoc and petitio princirii. The aspect of post hoc that 1S 1nvolved concerns the factor (P2 of the set of conditions of (2, p. 580) used to analyse the fallacy of post hoc when considering inferences from correlations to causal concluStOns. This particular factor is concerned with the non-symmetry of causal attributions. Its relevance is occasioned by the fact that we may know that there is some sort of causal connection between two conditions ยข and ~ without knowing which way the relation is to be directed. But enough hints. The problem is to sort out whether there has been a fallacy committed. If so, is it a petitio or a ~ost hoc? Or is there more than one fallacy, or is the fallacy a comb1nation of both? Another problem: who committed~efallacy, City Hall or the citizen's committee? Or did they somehow collaborate? References (1) C. I.. Hamblin, Fallacies, London, Methuen, 1970. (2) Joh~ Woods and Doublas Walton, 'Post Hoc Ergo Propter Hoc,' Rev1ew of Metaphysics, 30, 1977, 569 ... 5"93. John Woods University of Calgary Douglas Walton University of Winnipeg phi_---,_- iccl VOLUME VIII, Nos. 2-4 Marx W. Wartofsky, Editor FEUERBACH, MARX AND THE LEFT HEGELIANS This special issue, co-edited by Marx W. Wartofsky and Hans-Martin Sass, is a unique collection of original translations, major historical and philosophical studies, as well as first publication of letters and texts of the left Hegelians (notably, Feuerbach, Marx, Bruno Bauer, Edgar Bauer, Max Stirner and Moses Hess). This collection will interest both students (I\1Ij scholars. Mail to: P.O. Box 247 Boston University Station Boston. Massachusetts 02215 U.S.A. The price of this triple issue is $8.50 (300 pp.)