Two Concepts of Opposition, Multiple Squares

Abstract

This paper uses the resources provided by systems of illocutionary logic to characterize an opposition among assertive illocutionary acts that is parallel to incompatibility or inconsistency among statements. It is argued that opposition, or incoherence, among assertive illocutionary acts is more fundamental than inconsistency, and that our understanding of incoherence “underwrites” our conception of inconsistency. Diagrams are provided to illustrate relations of incoherence that are like such traditional diagrams as the square of opposition, which displays relations among statements.