Truth Checks

Knowledge and the Knower
Truth
Four theories of truth used to evaluate knowledge claims. Justified true belief and Gettier’s challenge.
Published

October 9, 2025

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Notes

Four truth checks — ways of evaluating whether a knowledge claim is true:

Check A claim is true when…

It matches observable reality

It fits consistently with other accepted beliefs

A relevant community of knowers agrees

Believing it produces good outcomes in practice

Linking truth to knowledge: The classical definition of knowledge as requires that a claim be true and justified and believed. Gettier (1963) showed this combination may not be sufficient — see the Stanford Encyclopedia of Philosophy entry for the full argument.