Who was Moritz Schlick?
Moritz Schlick (1882-1936) is famous for claiming that philosophy was dependent on science, intellectually. He was a philosopher who studied with the physicist Max Planck before arriving in Vienna, Austria, in 1922. His presence was the inspiration for the mathematician Hans Hahn to inaugurate the discussion group of the Vienna Circle, which, in addition to Hahn and Schlick, at first contained Otto Neurath (1882-1945) and the physicist Philip Frank. Rudolf Carnap (1891-1970) joined them in 1926.
Schlick was professor of the philosophy of inductive sciences at the University of Vienna, while he led the Vienna Circle. He believed that empirical knowledge was not about the content of experience, which could not be communicated, but about the form of experience. He maintained that all genuine philosophical problems and questions were either mathematical or logical, or could be solved by scientific investigation.
Schlick believed that this implied that philosophy had no subject matter of its own that was distinct from the sciences. However, unlike other logical positivists, he thought that ethics were practical and that moral goodness was simply whatever is approved by society; moral obligation could be studied as what is generally required by society. His main works include General Theory of Knowledge (second edition, 1925) and Problems of Ethics (translated, 1939).
Who was Rudolf Carnap?
Rudolf Carnap (1891-1970) is famous for his work on scientific verification. He received his Ph.D. from the University of Jena. He was a member of the Vienna Circle until he left Germany in 1935 to teach at the University of Chicago and the University of California at Los Angeles. In his early work he focused on the logical structure of language and what it implied about the world. In the 1940s, Carnap worked on logic and introduced the idea of a "state description," which is the linguistic form of a possible world, or the most complete description of the world that can be given in any language.
Unlike earlier logical positivists, Carnap addressed the problem of inconclusive evidence for actual scientific verification and the meaning of scientific terms. He argued for the use of probability in determining "degrees of confirmation" in place of absolute verification. Carnap's principle works include The Logical Structure of the World (1928; English translation, 1967), Philosophy and Logical Syntax (1935), Introduction to Semantics (1942), Formalization of Logic (1943), Meaning and Necessity: A Study in Semantics and Modal Logic (1947), and Logical Foundations of Probability (1950).
Who was Otto Neurath?
Otto Neurath (1882-1945) was a polymath who had begun by studying mathematics in Vienna, earning a doctorate in the subject in Berlin. During World War I he was assigned to the planning ministry by the Austrian government because he had earlier written about barter economies. The Marxist governments of Bavaria and Saxony hired him to implement their post-war socialist economies; he was charged with treason when the German government took over, although he was soon released. In graphic design, he contributed to the Viennese Social and Economic Museum with his invention of "Isotype," a system of symbols for iconographically presenting quantitative information to the public.
As a logical positivist, Neurath was the main architect of the manifesto of the Vienna Circle. Along with Rudolf Carnap (1891-1970), Bertrand Russell (1872-1970), John Dewey (1859-1952), and others, he advocated the Unity of Science project, which was to result in the International Encyclopedia of Unified Science that would unify language and method and interdisciplinary dialogue across the sciences. It was never published.
Neurath's ambition was to render the social sciences as predictive as the physical sciences. His main works include Through War Economy to Economy in Kind (1919), Personal Life and Class Struggle (1928), Empirical Sociology (1931), and Neurath-Carnap Correspondence (1943-1945), as well as numerous articles in edited collections, as well as work on The International Encyclopedia of Unified Science.
Neurath was married three times and his last wife, Marie, carried on his Isotype work after his death.