Logic is often conceived as a science of propositions, or of relations between propositions. There is an alternative view, however, defended by Meinong, Pfänder, Reinach and others, which sees logic as a science of “Sachverhalte” or states of affairs. A consideration of this view, which was defended especially by thinkers within the tradition of Brentano, throws new light on the problems of intentionality and of mental content. It throws light also on the development of logic in Poland. Here the influence (...) of Brentano’s student Kasimir Twardowski is especially important, and the paper concludes with a new interpretation of Tarski’s work on truth against the background of Twardowski’s thinking. (shrink)