The article focuses on the contribution of Austrian philosophy in the 19th century and the early 20th century to the development of the theory of terminology. Between 1860 and 1910, F. Brentano and his disciples A. Marty, A. Meinong, developed a multi-disciplinary philosophy (between psychology, linguistics, ontology, and epistemology) that started from Aristotle’s categories and resulted in a variety of theories and orientations that are today considered as crucial pre-requisites to ontology engineering, computational philosophy of science, and terminology studies. Husserl’s phenomenology and theory of meaning and Carnap’s constitutional ontology theory are also discussed in this re-construction of the development of the epistemological foundations of the theory of terminology as Eugen Wüster developed between the early 1920s and 1976.