Verificationism is a philosophical theory that asserts a statement is meaningful only if it can be empirically verified or is analytically true. This means that for a claim to be considered valid, it must be possible to test it through observation or experimentation, or it must be a tautology, like "all bachelors are unmarried men." The theory is closely associated with the Vienna Circle, a group of early 20th-century philosophers and scientists who promoted logical positivism. Verificationism challenges metaphysical claims, arguing that statements about the supernatural or abstract concepts lack meaning unless they can be tested or observed.