Logical positivism, an influential empiricist philosophical movement emerging in the late 1920s, sought to establish a philosophy as rigorous and scientific as empirical science itself. Its central tenet was the verification principle, which declared a statement cognitively meaningful only if it could be empirically verified or was a tautology, effectively dismissing metaphysics, ethics, and theology as meaningless. The movement originated primarily with the Vienna Circle, led by Moritz Schlick, and the Berlin Circle, flourishing through the 1930s and significantly influenced by figures like Ludwig Wittgenstein. However, by the 1950s, the verification principle faced intractable problems and mounting criticism from prominent philosophers such as Willard van Orman Quine and Karl Popper. These unresolved issues led to the movement's eventual decline and abandonment by the 1960s, famously prompting philosopher John Passmore to declare it "dead" in 1967.