Square of opposition (nonfiction)

Square of opposition from book by John Major, published Venice, 15th century.

The square of opposition is a diagram representing the relations between four propositions or four concepts.

The origin of the square can be traced back to Aristotle (nonfiction) making the distinction between two oppositions: contradiction and contrariety, although Aristotle did not draw any diagram.

Early diagrams were drawn several centuries later by Apuleius and Boethius.

Nonfiction cross-reference

• 

  Aristotle.

• Aristotle (nonfiction)

External links

• Square of opposition @ Wikipedia