In this article, a new, idealizing-hermeneutic methodological approach to developing a theory of philosophical arguments is presented and carried out. The basis for this is a theory of ideal philosophical theory types developed from the analysis of historical examples. According to this theory, the following ideal types of theory exist in philosophy: 1. descriptive-nomological, 2. idealizing-hermeneutic, 3. technical-constructive, 4. ontic-practical. These types of theories are characterized in particular by what their basic types of theses are. The main task of this (...) article is then to determine the types of arguments that are suitable for justifying these types of theses. Surprisingly, practical arguments play a key role here. (shrink)