Nominalism: See Universals. Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11. 

Prisoner’s Dilemma

Prisoner’s Dilemma: Famous contemporary problem of rational choice across philosophy and the social sciences in which the dilemma shows that purely self-maximizing decision does not effectively self-maximize. Myriad attempted solutions do not find the problem in the logical structure of choice itself in which pre-set dyadic choices rule out communicative cooperation and all interests beyond self-maximization. (See also Collective… Read More


Soundness: As a technical term in logic, soundness refers to that property which obtains when the premises of an argument are true and the argument is valid. Some consider soundness to be necessary and sufficient for an argument to be a good one. That is ,an argument that lacks either property is not a good argument;… Read More

Nonmonotonic Reasoning (Logic) :

Nonmonotonic Reasoning (Logic): The term “non-monotonic logic” covers a family of formal frameworks devised to capture and represent defeasible inference — that kind of everyday inference in which reasoners draw conclusions tentatively, reserving the right to retract them in the light of further information. Such inferences are called “non-monotonic” because the set of conclusions warranted on… Read More

Informal Logic

Informal Logic: The logic concerned with natural language argumentation. According to the authors, informal logic is the branch of logic whose task is to develop non-rigid formal standards, criteria, procedures for the analysis, interpretation, evaluation, criticism and construction of argumentation in everyday discourse and in disciplined inquiry. Source: ‘What is Good? What is Bad? The Value of All Values across Time,… Read More

Induction/Inductive Logic

Induction/Inductive Logic: Typically contrasted with deduction, inductive reasoning or induction is reasoning in which the conclusion follows from the premises, often with some assignable degree of probability or likelihood. One type of inductive inference is a generalization from the observed properties of a subset of a group to the conclusion that those properties will be found,… Read More


Dialogical: In argumentation theory, the approaches that take the primary setting for argument as the dialogue or exchange between two or more parties and that seek to formulate rules that govern those exchanges. A completely different concept would be Paolo Friere’s idea of dialogical pedagogy, which focuses on the importance of dialogue between teacher and student.… Read More


Dialectical/Dialectics: In its simplest terms, dialectics is the study of the norms of reasonable interpersonal or interactive argumentation. It is the study of the argumentation in which the roles of proponent and of opponent of a point of view are assumed and various goals of their interactive communication are considered. Argumentation is dialectical by virtue of… Read More

Defeasible Reasoning

Defeasible Reasoning: The forms of reasoning that are not as formal and rigorous as deductive reasoning. The term was brought to prominence by Pollock (1995), reasoning is defeasible when the corresponding argument, though not valid, is yet rationally meritorious. Pollock developed the term to help work through issues in epistemology. Given the relationship between epistemology and… Read More