There are exceptions to the principle of the excluded middle in logic
the verdict
SUPPORTED
the evidence backs this
confidence 88/100
Non-classical logical systems, such as intuitionistic logic, quantum logic, and certain paraconsistent or partial frameworks, explicitly reject or do not require the law of the excluded middle.
Evidence for · 4
On Some Intuitionistic Modal Logics
1977 · cited by 136
Discusses modal logics based on weaker logics than classical logic, such as intuitionistic systems.
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More for · 3
Intuitionistic Quantum Logic of an n-level System
2009 · cited by 45
Explicitly demonstrates that the law of the excluded middle fails in certain quantum and intuitionistic logical frameworks.
On Partial and Paraconsistent Logics
1999 · cited by 22
Examines partial logics and systems where fundamental classical principles like bivalence fail.
A Topological Surface Network Model of the Brain Suggests That There Is No Law of Excluded Middle in the Brain’s Logic
2026 · cited by 0
Argues and provides theoretical modeling suggesting that non-standard logics, specifically lacking the law of the excluded middle, can apply to complex systems like the brain.