The professorship researches the philosophy of the late Middle Ages and the Renaissance as a central period of upheaval in the history of European thought. In the field of tension between the historiographically powerful epochal boundaries of the "Middle Ages" and the "Early Modern Period", both the Aristotelian-influenced schools of thought at universities and humanist, often Platonic-oriented reform efforts outside the academic teaching contexts come into focus. The professorship's approach is to examine the simultaneity, interdependence and mutual transformation of knowledge models and philosophical traditions, which are traditionally described and differentiated from one another using terms such as "scholasticism" and "humanism" or "Aristotelianism" and "Platonism". Common historiographical classifications, which strictly separate them or even assign them to different eras, are historicized and critically reflected upon.

Methodologically, the professorship understands research in the history of philosophy not only as textual hermeneutics and discussion of problems, but also as an interdisciplinary interface. It also includes the philological indexing of sources and their critical edition, the investigation of material forms of knowledge transfer - manuscripts, libraries, copyists, etc. - as well as the analysis of social, religious and institutional contexts in which philosophy takes place as a concrete intellectual practice. At the same time, our work is guided by a pronounced disciplinary self-reflexivity: History of philosophy is related to its own emergence and development as a modern discipline and viewed in its context with the transnational history of knowledge and politics.

Two central, long-term initiatives are profile-forming: the DFG-funded critical edition of the complete Marginalia of Nicolaus of Cusa (1401–1464), including the study of his library and textual practices in the context of a philosophical history of reading (Marginalia Nicolai de Cusa); and the editorship of a book series on philosophical historiography (Brill's Series in Philosophical Historiographies), which serves as a platform for the discussion of theories, methods and the history of our discipline and whose aim is to make the history of philosophy visible as a site of negotiation of modern forms of rationality.