law of contradiction

American  

noun

Logic.

1. the law that a proposition cannot be both true and false or that a thing cannot both have and not have a given property.

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Example Sentences

The law of contradiction, after all, is not enforceable; if it were the jails would overflow.

From The Wall Street Journal • Oct. 2, 2016

For example, the law of contradiction states that nothing can both have a certain property and not have it.

From The Problems of Philosophy by Russell, Bertrand

This is the law of contradiction: how long will it take us to understand it?

From System of Economical Contradictions; or, the Philosophy of Misery by Proudhon, P.-J. (Pierre-Joseph)

Doubtless this law of contradiction was itself agreement, a restriction of personal liberty inconsistent with freedom; but the "larger synthesis" admitted a limited agreement provided it were strictly confined to the end of larger contradiction.

From The Education of Henry Adams by Adams, Henry

It follows from the logical law of contradiction that the proof of the existence theorem proves also the consistency of the axioms.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" by Various