The verification principle
A sentence is meaningful if and only if either
(1) it is tautological/analytic or
(2) it is verifiable using experience
Verification Principle applied to religious language
Cognitively meaningless because it does not meet either condition in the VP
Verification principle applied to moral language
Cognitively meaningless because it does not meet either condition in the VP
Verification principle applied to mental language
Cognitively meaningful but only if it is seen as referring to outward empirically verifiable behaviour