Contradiction /(?)/

Con·tra·dic·tion

Contradiction

n.
  1. An assertion of the contrary to what has been said or affirmed; denial of the truth of a statement or assertion; contrary declaration; gainsaying.
    His fair demands Shall be accomplished without contradiction.
  2. Direct opposition or repugnancy; inconsistency; incongruity or contrariety; one who, or that which, is inconsistent.
    can he make deathless death? That were to make Strange contradiction.
    We state our experience and then we come to a manly resolution of acting in contradiction to it.
    Both parts of a contradiction can not possibly be true.
    — Hobbes.
    Of contradictions infinite the slave.

Phrases & Compounds
Principle of contradiction
the axiom or law of thought that a thing cannot be and not be at the same time, or a thing must either be or not be, or the same attribute can not at the same time be affirmed and and denied of the same subject; also called the law of the excluded middle.