Verificationism

Hempel came to acknowledge that Logical Positivism's verificationism was untenable, but argued that falsificationism was equally untenable on logical grounds alone.

In verificationism, only the verifiable was scientific, and thus meaningful (or cognitively meaningful), whereas the unverifiable, being unscientific, was meaningless "pseudostatements" (just emotively meaningful).

Popper's own falsificationism, thus, is not only an alternative to verificationism, it is also an acknowledgement of the conceptual distinction that previous theories had ignored.