Semiotic square
The semiotic square, also known as the Greimas square, is a tool used in structural analysis of the relationships between semiotic signs through the opposition of concepts, such as feminine-masculine or beautiful-ugly, and of extending the relevant ontology. The semiotic square, derived from Aristotle's logical square of opposition, was developed by Algirdas J. Greimas, a Lithuanian-French linguist and semiotician, who considered the semiotic square to be the elementary structure of meaning.