The Vienna Circle was a group of philosophers and scientists organized in Vienna under Moritz Schlick. They met weekly, for the most part, beginning in 1922 and ending in 1932, when Schlick was shot to death by an irate graduate student. Many members left Austria during the rise of the Nazi party, and the circle had dissolved by 1936. Their approach to philosophy came to be known as "Logical Positivism."
Prominent members of the Circle included Rudolf Carnap, Otto Neurath, Herbert Feigl, Philipp Frank, Friedrich Waissman, Hans Hahn. They were visited on occasion by Hans Reichenbach, Kurt Gödel, Carl Hempel, Alfred Tarski, W. V. Quine, and A. J. Ayer (who popularized their work in Britain). Karl Popper, though he never attended the Circle's meetings, was influential in the reception and criticism of their doctrines.
For some time a few of the group's members met regularly with Ludwig Wittgenstein.