"Authority" is a term widely used by scholars from various fields of studies, including the history of philosophy, but its actual meaning often remains obscure. This paper aims to show how a philosophical reflection on the structure of epistemic authority can shed light on this phenomenon and facilitate a better understanding of its meaning in historical research. It will present an analytical model that serves as a tool to get a better grasp on authority relations in historical texts. The benefit of the described model will be demonstrated by a case study on the question of authority in Neoplatonism.