 The movement shifted, thus, into a milder variant bettered termed "logical empiricism" or, but still a neopositivism, led principally by Rudolf Carnap, Hans Reichenbach, and Carl Hempel.Amid increasingly apparent contradictions in neopositivism's central tenets—the verifiability principle, the analytic/synthetic division, and the observation/theory gap—Hempel in 1965 abandoned the program a far wider conception of "degrees of significance".This signaled neopositivism's official demise.