Informal logic encompasses the principles of logic and logical thought outside of a formal setting (characterized by the usage of particular statements). However, the precise definition of "informal logic" is a matter of some dispute. Ralph H. Johnson and J. Anthony Blair define informal logic as "a branch of logic whose task is to develop non-formal standards, criteria, procedures for the analysis, interpretation, evaluation, criticism and construction of argumentation." This definition reflects what had been implicit in their practice and what others were doing in their informal logic texts. Informal logic is associated with informal fallacies, critical thinking, the thinking skills movement and the interdisciplinary inquiry known as argumentation theory. Frans H. van Eemeren writes that the label "informal logic" covers a "collection of normative approaches to the study of reasoning in ordinary language that remain closer to the practice of argumentation than formal logic."
History Informal logic as a distinct enterprise under this name emerged roughly in the mid-20th century as a sub-field of philosophy. The naming of the field was accompanied by the appearance of a number of textbooks that rejected the symbolic approach to logic on pedagogical grounds as inappropriate and unhelpful for introductory textbooks on logic for a general audience, for example Howard Kahane's Logic and Contemporary Rhetoric, subtitled "The Use of Reason in Everyday Life", first published in 1971. Kahane's textbook was described on the notice of his death in the Proceedings And Addresses of the American Philosophical Association (2002) as "a text in informal logic, [that] was intended to enable students to cope with the misleading rhetoric one frequently finds in the media and in political discourse. It was organized around a discussion of fallacies, and was meant to be a practical instrument for dealing with the problems of everyday life. [It has] ... gone through many editions; [it is] ... still in print; and the thousands upon thousands of students who have taken courses in which his text [was] ... used can thank Howard for contributing to their ability to dissect arguments and avoid the deceptions of deceitful rhetoric. He tried to put into practice the ideal of discourse that aims at truth rather than merely at persuasion. (Hausman et al. 2002)" Other textbooks from the era taking this approach were Michael Scriven's Reasoning (Edgepress, 1976) and Logical Self-Defense by Ralph Johnson and J. Anthony Blair, first published in 1977. Earlier precursors in this tradition can be considered Monroe Beardsley's Practical Logic (1950) and Stephen Toulmin's The Uses of Argument (1958). The field perhaps became established as a separate field of study through the First International Symposium on Informal Logic held in 1978. Although initially motivated by a new pedagogical approach to undergraduate logic textbooks, the scope of the field was basically defined by a list of 13 problems and issues which Blair and Johnson included as an appendix to their keynote address at this symposium:
the theory of logical criticism the theory of argument the theory of fallacy the fallacy approach vs. the critical thinking approach the viability of the inductive/deductive dichotomy the ethics of argumentation and logical criticism the problem of assumptions and missing premises the problem of context methods of extracting arguments from context methods of displaying arguments the problem of pedagogy the nature, division and scope of informal logic the relationship of informal logic to other inquiries David Hitchcock argues that the naming of the field was unfortunate, and that philosophy of argument would have been more appropriate. He argues that more undergraduate students in North America study informal logic than any other branch of philosophy, but that as of 2003 informal logic (or philosophy of argument) was not recognized as separate sub-field by the World Congress of Philosophy. Frans H. van Eemeren wrote that "informal logic" is mainly an approach to argumentation advanced by a group of US and Canadian philosophers and largely based on the previous works of Stephen Toulmin and to a lesser extent those of Chaïm Perelman. Alongside the symposia, since 1983 the journal Informal Logic has been the publication of record of the field, with Blair and Johnson as initial editors, with the editorial board now including two other colleagues from the University of Windsor—Christopher Tindale and Hans V. Hansen. Other journals that regularly publish articles on informal logic include Argumentation (founded in 1986), Philosophy and Rhetoric, Argumentation and Advocacy (the journal of the American Forensic Association), and Inquiry: Critical Thinking Across the Disciplines (founded in 1988).
… excerpt ends here. Continue reading the full article.
