Informalizing Formal Logic

Studia Logica, 2009

n the current paper, we re-examine how abstract argumentation can be formulated in terms of labellings, and how the resulting theory can be applied in the field of modal logic. In particular, we are able to express the (complete) extensions of an argumentation framework as models of a set of modal logic formulas that represents the argumentation framework. Using this approach, it becomes possible to define the grounded extension in terms of modal logic entailment.

Informal Logic, 1988

 Nowadays researchers working in various fields study the issues of argument. They represent different approaches which distinguish with theoretical and practical comprehension of argument problems. Informal study of argument is one of the approaches. The key reason of its appearance was the criticism of formal logic in the late 20th century.

Godden, D., Groarke, L. and Hansen, H. (2011). Informal logic and argumentation: An Alta conversation. In R. Roland (Ed.), Reasoned argument and social change: Selected papers from the 17th biennial conference on argumentation (pp. 48-62). Washington, DC: NCA. Alta, Utah, July 28-31, 2011., 2011

Informal logic is both a pedagogical and a theoretical endeavour. It began as a response to formal logic which attempted to provide an analysis and assessment of argument which is better suited to the study of informal arguments -- often described as “natural language” or “everyday” arguments. “IL” (as it is sometimes designated) is a field rather than a school of thought, and characterized by many different and sometimes contrary approaches and perspectives. While its development is characterized by an ever broadening interest in informal argumentation in all its forms, it maintains a focus on inference understood in terms of the relationship between premises and conclusions, and on the normative analysis of arguments in this sense. In the course of its development it has been influenced, and continues to interact with dialectical and rhetorical approaches to argument. This paper is intended as catalyst to further discussion and debate.

D. Walton and T. F. Gordon, Proceedings of the 10th International Conference of the Ontario Society for the Study of Argument (OSSA), ed. D. Mohammed and M. Lewinski, Windsor, Ontario, OSSA, 2013, 1-13.

This paper presents a formalization of informal logic using the Carneades Argumentation System, a formal, computational model of argument that consists of a formal model of argument graphs and audiences. Conflicts between pro and con arguments are resolved using proof standards, such as preponderance of the evidence. Carneades also formalizes argumentation schemes. Schemes can be used to check whether a given argument instantiates the types of argument deemed normatively appropriate for the type of dialogue.

2009

2015

In this thesis I present an exploration into the concept of ‘argument’ in informal logic. I have separated the work into three major areas: the historical antecedents to the informal logicians, the Windsor group of informal logicians, and recent developments in informal logic and the concept of ‘argument.’ In doing so I provide insight into the concept of ‘argument’ within informal logic.

Walton, D. and Godden, D. (2007). Informal logic and the dialectical approach to argument. In H.V. Hansen and R.C. Pinto (Eds.), Reason Reclaimed (pp. 3-17). Newport News, VA: Vale Press., 2007

Undoubtedly, Ralph H. Johnson and J. Anthony Blair are two of the patriarchs of informal logic (IL), and they remain its most recognized exponents. The informal logic movement initially began as a rejection of the tools of formal logic as an effective means of analysing and evaluating everyday reasoning and argumentation. As it developed, IL began to adopt a dialectical conception of its subject matter, and started to utilize the theoretical and methodological tools associated with this approach. This paper explores the influence of the dialectical conception of argument on the development of informal logic. Noting that neither Blair nor Johnson has embraced a dialogic approach to the dialectical, we situate Walton’s dialog-based approach in relation to that of informal logic.

E. C. W. Krabbe and D. Walton, Keeping in Touch with Pragma-Dialectics and Computation, ed. E. Feteris, B. Garssen and F. Snoeck Henkemans. Amsterdam: Benjamins, 2011, 245-263.

In this paper we offer an explanation of how formal dialectical systems are useful for modeling important aspects of argumentation, like dealing with fallacies. This aim is accomplished by presenting a brief outline of the main characteristics and rules of two representative systems, one of the Hamblin type and one of the Lorenzen type. We use these two systems to discuss aspects of argumentation that have turned out to be important, showing that the best way to apply such systems is to build what we call a laboratory of rules.

Argumentation in Artificial Intelligence, 2009