The Many Faces of Inconsistency

Abstract

To think about inconsistencies involves reflecting on several basic notions widely used in order to talk about human knowledge and actions, such as negation, opposition, denial, assertion, truth, falsity, contradiction and incompatibility, just to name the more perspicuous ones. All of them are regularly used in natural language and for each one several definitions or conceptions have been proposed throughout the history of Western thought. That being so we tend to think that we have a good enough intuitive understanding of them. Yet a closer examination shows many ways in which “contradiction” and related words can be understood. Thus, a more precise definition would help to clarify their meaning and assist us to use them in a more appropriate manner. In this paper I will try to clarify these notions and thus make a terminological proposal. The general background will be the reflexion on paraconsistency. A main purpose will be to show that the confusion between contraries and contradictories—although they were clearly distinguished in the original square of opposition—is very common and it paves the way to the rejection of all forms of “inconsistencies” without making distinctions, and also to the wrong assumption that regarding all the main aspects the effects of contrary opposition are equivalent to the ones of contradictory opposition.