CONTRADICTORY.—The CONTRADICTORY of any Term is its mere negation,
e.g., not-white is the contradictory of white. So the contradictory of any
is its mere negation, e.g., Some men are not white is the contradictory of
men are white. The contradictory of the Universal Affirmative (A) is the
Particular Negative (0); of the Universal Negative (E) the Particular
Affirmative (I). Of two contradictory propositions, one is necessarily true and
the other false.