A law in (2-valued) logic which states there is no third alternative to truth or falsehood. In other words, for any statement , either or not- must be true and the other must be false. This law no longer holds in three-valued logic or fuzzy logic.

# Law of the Excluded Middle

## See also

Bivalent, Fuzzy Logic, Three-Valued Logic## Explore with Wolfram|Alpha

## References

Erickson, G. W. and Fossa, J. A.*Dictionary of Paradox.*Lanham, MD: University Press of America, pp. 64-65, 1998.

## Referenced on Wolfram|Alpha

Law of the Excluded Middle## Cite this as:

Weisstein, Eric W. "Law of the Excluded Middle."
From *MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/LawoftheExcludedMiddle.html