In 1963, he moved back to Vienna and was a research fellow and assistant professor at the Institute of Advanced Studies in philosophy of science, economics, social and political sciences, and game and decision theory. During this time, he was also a lecturer at the University of Vienna. In 1967, due to an unfavorable political and scientific climate in post-war Austria, he was unable to obtain a tenured faculty position in Austria and so he moved to Lincoln, Nebraska and joined the department of philosophy at the university of Nebraska-Lincoln as a full professor. In 1970, he founded the journal Theory and Decision, an international journal for philosophy and methodology of the social sciences. The founding of the journal was, in part, a reaction to the dogmatic, subjective, and metaphysical approaches he had encountered in Europe prior to coming to the United States. His vision was that "Theory and Decision" would help found a philosophy of the social science based on three premises:  In 1974, he cofounded "Theory and Decision Library" also based on these three principles. Indeed, Eberlein and Berghel (1988) concluded:  It was essentially Werner Leinfellner's accomplishment that the ideal of logical empiricism in the 1930s and 1940s, to create a "unified science", was replaced by that of a "methodological unity of science". Accordingly... the THEORY AND DECISION school of the philosophy of the social science can substantiate his claim: "... There are no longer any methodological differences at issue". Certainly the term "methodological" has to be interpreted in a broad sense, implicating the unity of science due to common standards of theory formation and to the fact that theories are the methodological basic units of the social science disciplines. Furthermore, "methodological unity", in the context of this journal and library, refers to the continuously differentiated and integrated unity of an undogmatic, pluralistic philosophy of the social sciences (page xii). In 1976, Werner Leinfellner together with his wife Elisabeth Leinfellner cofounded the Austrian Wittgenstein Society and the International Wittgenstein Symposium in Kirchberg am Wechsel. In 1986, he became professor emeritus at the University of Nebraska-Lincoln and returned to Vienna Austria as professor at the Vienna University of Technology. In 1991, he became a member of the Science Board at the Institute Vienna Circle. Its goal is to document the continued development of the Vienna Circle's work in science and the continued application of logical-empirical thought to the philosophy of science and thereby it continues Leinfellner's goal of breaking away from irrational, dogmatic, fundamentalist though.