The concept of discourse is of high importance for non-positivist research in information systems. At the same time there are different concepts of discourse that are used simultaneously and often without clear recognition what their choice entails. This paper therefore aims to clarify the conceptual basis of working with discourses in IS research. In order to do this it describes and compares the notions of discourse as we find them in two of the most influential discourse theories, namely those by Michel Foucault and Jürgen Habermas. A comparison of the two from the point of the IS researcher argues that the most important feature that Foucault's and Habermas's discourse theories have in common is their critical intention. From ...