Concept
Informal logic
Overview
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."
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
Possible passages
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No; the name mathematicians give it would suffice to prove this. In mathematics logic is called _analysis_ and analysis means _division_, _dissection_. It can have, therefore, no tool other than the scalpel and the microscope. Thus logic and intuition have each their necessary rôle. Each is indispensable.
Henri Poincaré, The Foundations of Science
States what Informal logic is.
A distinct idea is defined as one which contains nothing which is not clear. This is technical language; by the _contents_ of an idea logicians understand whatever is contained in its definition. So that an idea is _distinctly_ apprehended, according to them, when we can give a precise definition of it, in abstract terms. Here the professional logicians leave the subject; and I would not have troubled the reader…
Charles S. Peirce, Chance, Love, and Logic
States what Informal logic is.
(2) Logic is the study of thought pure and simple, or of the pure thought-forms. In the ordinary sense of the term, by thought we generally represent to ourselves something more than simple and unmixed thought; we mean some thought, the material of which is from experience. Whereas in logic a thought is understood to include nothing else but what depends on thinking and what thinking has brought into existence. It…
Georg Wilhelm Friedrich Hegel, The Logic of Hegel
States what Informal logic is.
Philosophers who discussed Informal logic
Related ideas
- World Congress of Philosophy
- Formal language
- Argumentation theory
- Philosophy
- Stephen Toulmin
- Informal fallacy
- Metaphysics
- Natural language
- Validity (logic)
- Psychology
- Plato
- Theory of forms
- Critical thinking
- Aristotelianism
- Logical form
- Structure (mathematical logic)
- Logic
- Dialectic
- Deductive reasoning
- Premise
- Proposition
- Monroe Beardsley
- Robert Fogelin
- Michael Scriven
Opposing perspectives
Place in the tradition
Part of Inference.