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
Kings Park, New York

... of age or older. The median age is 38 years. For every 100 females there are 94.9 males. For every 100 females age 18 and over, there are 92.0 males. The median income ...

 
 
 
This page was created in 41.7 ms