The term "Logical Positivism" was coined some thirty years ago to characterize the standpoint of a group of philosophers, scientists and mathematicians who gave themselves the name of the Vienna Circle. Since that time its reference has been extended to cover other forms of analytical philosophy; so that disciples of Bertrand Russell, G. E. Moore or Ludwig Wittgenstein at Cambridge, or members of the contemporary Oxford movement of linguistic analysis may also find themselves described as logical positivists. This wider usage is especially favored by those who are hostile to the whole modern development of philosophy as an analytical rather than a speculative enquiry. They wish to tar all their adversaries with a single brush. This is irritating to the analysts themselves who are rather more sensitive to their differences; they would prefer that the appellation of "logical positivist" be reserved for those who share the special outlook of the Vienna Circle. In compiling this anthology, I have not been quite so strict. I have drawn mainly on the writings of the members of the Vienna Circle, or of those who stand closest to them, but I have also included several pieces which fall outside this range. They are all, in some sense, analytical but the scope of what I regard as analytical philosophy is wide. It allows for serious disagreement, not only over technical niceties, but on major points of doctrine, including the method and purpose of analysis itself.
The Vienna Circle came into being in the early 1920's when Moritz Schlick, around whom it centered, arrived from Kiel to become professor of philosophy at the University of Vienna. On the philosophical side its leading members, besides Schlick himself, were Rudolf Carnap, Otto Neurath, Herbert Feigl, Friedrich Waismann, Edgar Zilsel and Victor Kraft; on the scientific and mathematical side, Philipp Frank, Karl Menger, Kurt Gödel and Hans Hahn. At the beginning, it was more of a club than an organized movement. Finding that they had a common interest in, and a . . .