»Austrian Civil Procedure's Dichotomy of a Notion Concerning the Matter in Dispute: a Comparison between the National Matter in Dispute Doctrine and the European Civil Procedure Law's ›Heart of the Two Actions‹-Theory« In civil proceedings before an Austrian court, both the autonomous notion concerning the matter in dispute of European Civil Procedure Law, the so-called » heart of the two actions«-theory of the ECJ, and the national one may be applicable at the same time. The paper analyses the similarities, but also the differences between those concepts. In particular, the EU autonomous notion of res judicata postulated by the ECJ in ›Gothaer Allgemeine Versicherung vs. Samskip‹ is critically examined.weiterlesen