Abstract

It is argued that the theory of opposition is in position to contribute as a formal method of conceptual engineering, by means of an increasing dichotomy-making process that augments the number of elements into any structured lexical field. After recalling the roots of this theory and its logical tenets, it is shown how the processes of expansion and contraction of discourse can modify a lexical field and, with it, our collective representation of ideas. This theory can also bring some order to the question of disagreement in philosophical discourse: what do philosophers disagree about; how can we clarify the distinction between verbal disagreement (focused on words) and substantive disagreement (focused on things)? The ensuing construction of conceptual systems will be exemplified through three case studies of philosophy: desire, truth judgment, and the left–right political divide. The construction rules of such systems resort to the theory of opposition, which intends to improve our understanding of what entails either agreement or disagreement about the meaning of concepts. Such a better understanding of philosophical discourse relies on its formalization in terms of closed lexical fields, thereby leading to a comparative analysis of concepts in light of logical relations between their definitions.