Paradox of the Day

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p ∧ ¬B(p)

Moore’s Paradox

G. E. Moore · 1942

The puzzle

“It is raining, but I don’t believe it is raining.”
Domain
Belief · Assertion
Attribution
G. E. Moore
Date
1942

Note

The sentence isn’t a contradiction. Both halves can easily be true: it really is raining, and I really lack the belief. But asserting it is incoherent. Moore noticed that an utterance commits the speaker to believing it, so to assert p and at the same time deny believing p is to reveal the very belief you are disclaiming. Wittgenstein found the example deeply suggestive and used it to argue that first-person psychological language doesn’t describe an inner state at all but expresses commitment. Modern philosophers of language treat Moore’s sentences as the central evidence for the rule that assertion has belief-conditions built in, separate from truth-conditions. Saying it makes it false in a way that isn’t about the world.

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