Vienna Circle

The Vienna Circle (in German: der Wiener Kreis) was the name of a group of philosophers who began meeting around the University of Vienna in 1922.
Many famous philosophers were members. Some of its members were:
Most followed the philosophy that came to be known as logical positivism.
Ludwig Wittgenstein's, 1921 book "Tractatus Logico-Philosophicus" formed the basis for the group's ideas. Wittgenstein himself insisted that they did not understand him correctly and took to quietly reading poetry to himself during their meetings. 
The Vienna Circle was broken up when the Nazi party came to power in Germany in 1933, many of its members moved to the USA, where they became teachers in several universities. 
The Vienna Circle's influence on 20th century philosophy was very large.