New Essays in Informal Logic

Future Human Image, 2018

The challenges of the global time require new solutions and up-to-date ways of thinking and communication. These challenges call for the ability to use critical thinking to face the ever-changing world and the ability to maintain a dialog based on the effective skills of communication. Studies in the fields of logic and argumentation theory are of particular importance in this regard. Nowadays they can be presented as a mix of theoretical and practical approaches. In this paper, I will present my reflections on informal logic, which was formed in the late 1970s. Unfortunately, in spite of numerous papers, books, and text-books published over the last forty years, consensus on many issues in this field has not been achieved so far. Therefore, it is difficult to treat informal logic as one of the well-defined approaches to argumentation. The goal of this paper is to take a look at the place of informal logic in state-of-the-art study of argumentation by clarifying its subject matter and figuring out the realm to which informal logic belongs. Keywords: logic, informal logic, formal logic, theory of argumentation, epistemology, cognitive science, real argument

Lecture Notes in Computer Science, 2014

This paper deals with an approach to opponent-modelling in argumentation-based persuasion dialogues. It assumes that dialogue participants (agents) have models of their opponents' knowledge, which can be augmented based on previous dialogues. Specifically, previous dialogues indicate relationships of support, which refer both to arguments as abstract entities and to their logical constituents. The augmentation of an opponent model relies on these relationships. An argument external to an opponent model can augment that model with its logical constituents, if that argument shares support relationships with other arguments that can be constructed from that model. The likelihood that the constituents of supporting arguments will in fact be known to an opponent, varies according to support types. We therefore provide corresponding quantifications for each support type. Definition 2. A knowledge base (KB) in an AS is a pair (K, ≤) where K ⊆ L and K = K n ∪ K p where these subsets of K are disjoint: K n is the (necessary) axioms (which cannot be attacked); and K p is the ordinary premises (on which attacks succeed contingent upon preferences), and where ≤ is a preordering on the ordinary premises K p. Arguments are now defined, where for any argument A, Prem returns all the formulas of K (premises) used to build A; Conc returns A's conclusion; Sub returns all of A's sub-arguments; and Rules returns all rules in A.

2003

The explosion of developments in logic over the past 25 years deriving from the informal logic movement, as complemented by studies in argumentation theory, pragma-dialectics, critical thinking, and the new rhetoric, has been astounding. A signature feature of this compassing movement treating argumentation 1 is an extraordinary confluence of disciplines -ranging from psychology, sociology, linguistics, rhetoric, and classical textbook logic to phenomenology, and cognitive science. This confluence has dramatically enriched and added new vitality to discussions about argumentation. It has also tagged this movement as broadly multi-dimensional and as replete with trends not all of which are equally compatible and some even contrary. This situation has encouraged some critics to mark this as a serious limitation, citing the movement's lack of definition and apparent aimlessness; they might even venture to predict its eventual dissolution, suggesting that its varied influences will become reabsorbed into traditional disciplines. Nevertheless, informal logicians consider this situation not to detract from but to be a positive feature of the movement, and they tout its special revolutionary and non-conventional nature.

Informal Logic, 1991

What rational foundation underlies argument-critical judgements? What are the canons of argument criticism and how are they to be "justified"? This paper explores an analogy between art-and argument-criticism and argues that the analogy promises not only to illuminate the nature of argument criticism and capture the central goals of instruction in informal logic, but also to resolve fundamental problems at the foundations of normative theory of argument concerning the "justification" of standards of reasoning.

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.