Encyclopedia > Square of opposition

  Article Content

Square of opposition

The Square of opposition is a term from the study of Aristotelian logic, in which the logical relationship between various types of sentences is spelled out:

These rules apply:

  1. At least one of the universal statements must be false.
  2. Contradictory statements have opposite truth values.
  3. Universal statements entail their subalterns.
  4. At least one of the particular statements must be true.

Only the first two rules are explicitly stated by Aristotle (in his work, De Interpretatione) but the other two can be inferred.



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Father Damien

... at the leper colony (see Kalawao County, Hawaii), he contracted the disease, from which he died at the colony. He is the patron of lepers and outcasts, and was recently ...

 
 
 
This page was created in 39.4 ms