ABSTRACT
Logical empiricism-also known as logical positivism or neopositivism (there is no principled distinction to be drawn here, see below, section 3)— was a philosophical movement that spanned less than half of the 20th century but left a lasting if controversial legacy. Originating in the 1920s in the Vienna Circle around Moritz Schlick and in the Berlin group around Hans Reichenbach, logical empiricism sought an understanding of the nature of modern science after the revolutionary developments in mathematics and physics that culminated in Einstein’s theories of relativity, an understanding that neither traditional empiricism nor transcendental idealism was held to be able to supply. In doing so, logical empiricists built to varying degrees on the pioneering works of Gottlob Frege, Bertrand Russell, and Ludwig Wittgenstein in logic and of Ernst Mach, Henri Poincaré, and Pierre Duhem in philosophy of science. Exiled from Central Europe by National Socialism, by the 1940s prominent logical empiricists like Rudolf Carnap, Herbert Feigl, C. G. Hempel, and Reichenbach himself were able to establish themselves at North American universities and, along with like-minded native and former visitors like Ernest Nagel and W. V. O. Quine, started to inuence a new generation of philosophers. (Schlick was murdered in 1936 in Vienna.) While most of the solutions proposed by logical empiricists no longer command acceptance, many of the problems they identied continue to dene the eld of philosophy of science.
