verifiability

In logic and philosophy, the feature of a proposition that enables us to check that it is true. A verifiable proposition has to be contingent; that is, it must be possible that it is false.

Twentieth-century positivists and empiricists, seeking to dismiss metaphysics and theology as nonsense, made verifiability into a theory of meaning that requires meaningful propositions to have a method of verification. Since few statements are conclusively verifiable, English philosopher A J Ayer and others sought to defend ‘weak’ verifiability in which provision of evidence would suffice.