law of excluded middle

American  

noun

Logic.

1. the principle that any proposition must be either true or false.

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Example Sentences

Take, for example, the law of excluded middle in the form ‘all propositions are true or false.’

From The philosophy of B*rtr*nd R*ss*ll by Various

For, on the supposition, a thing would be something else, whereas all that the law of excluded middle demands is that it should either be itself or not.

From Deductive Logic by Stock, St. George William Joseph

Neither would the law of excluded middle be infringed.

From Deductive Logic by Stock, St. George William Joseph

To mention in the same breath the law of excluded middle, and two contradictions with a mean between them, requires a hardihood unparalleled in the history of philosophy, except by Hegel.

From Know the Truth; A critique of the Hamiltonian Theory of Limitation by Jones, Jesse H.

The law of excluded middle holds only with regard to contradictories.

From Deductive Logic by Stock, St. George William Joseph