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∀p(p → ⋄Kp) ⊢ ∀p(p → Kp)
Knowability Paradox: "each truth is knowable, but only if each truth is (at some time) known."
where variables p range over propositions; ⋄ is the normal modal operator, ‘it is possible that’; and K is the epistemic operator ‘it is known (by somebody at some time) that’.

Originally posted by knowability.googlepages.com:

The conclusion of the result, viz., ∀p(p → Kp), sometimes called the omniscience principle, is obviously false. For lack of a better label, ‘omniscience principle’ is often used for the conclusion of Fitch’s paradox. The label is however somewhat misleading, since it suggests that there is a time at which some individual (or community) knows every truth. The principle however does not say this much. It says merely that for each truth there some time or other at which it is known.

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