To submit a contribution send a one page abstract before April 20 2020 to: leuven2020@square-of-opposition.org. All talks related to the square of opposition are welcomed, in particular those falling under the categories below. Diagrammatic and Artistic works related to the square of opposition are also welcomed: 

HISTORY OF THE SQUARE 

• Aristotle, Apuleius, Boethius 
• Avicennes, oppositions in Arabic thought 
• Oppositions in Indian and Chinese thoughts 
• Buridan, Port Royal, Leibniz 
• Vasiliev, Hamilton, Schröder, Frege 
• Sesmat, Blanché 
• Piaget, Lacan, Greimas 

APPLICATIONS OF THE SQUARE 

• proof theory, model theory 
• debates and politics 
• psychoanalysis 
• music and arts 
• religion, theology 
• ethics and law 
• perception and cognition 

VARIATIONS OF THE SQUARE 

• squares of quantification 
• alethic, deontic, doxatic modal squares 
• semiotic squares 
• metalogical squares 
• paraconsistent and paracomplete squares 
• intuitionistic and linear squares 

EXTENSIONS OF THE SQUARE 

• cubes 
• hexagons and stars 
• octagons and decagons 
• polyhedra and polysimplexes 
• n-opposition theory 
• borromeans