Interpretar un texto filosófico supone procurar descifrar su significado, identificar sus tesis y aislar sus argumentos. Desarrollar un texto filosófico, en cambio, consiste en seleccionar ciertas ideas fundamentales, valiosas aunque necesitadas de afinamiento, y lograr su mejor formulación. Lógica Viva, la obra filosófica más importante de Vaz Ferreira, ha merecido diversas interpretaciones y desarrollos. En particular, esto ha ocurrido con su capítulo dedicado a la falsa oposición. El objetivo principal de esta nota es reconocer cinco enigmas en tal capítulo, relevantes (...) para una interpretación y decisivos para ciertos desarrollos. Expresados sucintamente en forma de interrogantes los mismos podrían exponerse así: ¿cómo entender, en este contexto, oposición?, ¿cuál es el papel que, en la caracterización del paralogismo, juega la ejemplificación?, ¿cuán relevantes son, en tal labor, las dimensiones literal y no-literal?, ¿en qué consiste el “mal argumento” que se considera falsa oposición?, ¿cómo equivoca y cómo persuade el mismo? Se recurre además a un modelo de análisis argumental (denominado M), inspirado en las ideas de Vaz Ferreira, a los efectos de mostrar cómo su uso auspicia, por una parte, un tratamiento explícito de estos enigmas y, por otra, desafiado por estos, cómo su aplicación pueda quizá sugerir líneas prometedoras de interpretación y/o desarrollo. Estas páginas pretenden asimismo ilustrar ciertas relaciones entre ambas actividades. (shrink)

The nontechnical ability to identify or match argumentative structure seems to be an important reasoning skill. Instruments that have questions designed to measure this skill include major standardized tests for graduate school admission, for example, the United States-Canadian Law School Admission Test (LSAT), the Graduate Record Examinations (GRE), and the Graduate Management Admission Test (GMAT). Writers and reviewers of such tests need an appropriate foundation for developing such questions--they need a proper representation of phenomenological argumentative structure--for legitimacy, and because these (...) tests affect people's lives. This paper attempts to construct an adequate and appropriate representation of such structure, that is, the logical structure that an argument is perceived to have by mature reasoners, albeit ones who are untrained in logic. (shrink)

In this paper I focus on the fallacy known as Complex Question or Many Questions. After a brief introduction, in Sect. 2 I highlight its pragmatic dimension, and in Sect. 3 its dialectical dimension. In Sect. 4 I present two accounts of this fallacy developed in argumentation theory, Douglas Walton’s and the Pragma-Dialectics’, which have resources to capture both its pragmatic and its dialectical nature. However, these accounts are unsatisfactory for various reasons. In Sect. 5 I focus on the pragmatic (...) dimension of the fallacy and I suggest amendments to the accounts mentioned drawing on the study of the phenomenon of presupposition in theoretical pragmatics. I argue that the central notion in the definition of the fallacy is that of an informative presupposition. In Sect. 6 I focus on the dialectical dimension of the fallacy. This dimension needs to be explicitly acknowledged in the definition of the fallacy in order to distinguish it from a different, non-dialectical, fallacious argumentative move involving presuppositions. (shrink)

According to the Asymmetry Thesis, whereas there are many kinds of argument-forms that make at least some of their instances valid, there is none that makes any of its instances invalid. To refute this thesis, a counterexample has been produced in the form of an argument-form whose premise-form's instances are all logically true and whose conclusion form's instances are all logically false. The purpose of this paper is to show that there are many more kinds of argument-forms that make some (...) of their instances invalid and that, hence, are counterexamples refuting the Asymmetry Thesis. (shrink)

We are pleased to release this edition of Ralph Johnson’s The Rise of Informal Logic as Volume 2 in the series Windsor Studies in Argumentation. This edition is a reprint of the previous Vale Press edition with some typographical errors and other minor mistakes corrected. The prime motive for gathering Ralph H. Johnson’s essays under one cover is their clear articulation of the goals, concerns and problems of the discipline of informal logic. To my knowledge all of the published articles, (...) even of the 1980s, are still in print. But some are obtainable only by special request of a journal back issue. Their availability, even their existence, is not nearly widely enough known, and this volume is dedicated to remedying that disservice to those currently working in the field of informal logic, critical thinking, argumentation, and practical reasoning. Three of these sixteen pieces appear here in print for the first time. The previously published pieces have appeared from 1980 to 1992 as chapters in collective works or as articles in journals, and these in turn published in Canada, USA, The Netherlands and Belgium. It is hoped that gathering this hitherto scattered material under one cover will contribute to a greater understanding of what informal logic is, and to an enhanced sense of the impact of Johnson’s ideas. A discipline of informal logic might exist today without the writings of Johnson and his frequent co-author, J. Anthony Blair. But it would almost certainly be quite different from what it actually is. (shrink)