This article explores critically the history and nature of a hermeneutic assumption often guiding interpretations of Plotinus’ philosophy produced in the 18th century and onwards, namely that Plotinus advanced a system of philosophy. It is argued that this assumption was employed on Plotinus’ writings relatively late, in the 18th and 19th centuries, and that it was primarily made possible by Brucker’s methodology for history of philosophy, dating from the 1740s, in which the concept system of philosophy was essential. It is observed that the concept was absent in Ficino’s commentary from the 15th century, and that it remained absent in interpretative works produced between the 15th and 18th century. It is also argued that it is erroneous to assume that Plotinus presented a system of philosophy, or intended to do so — we do not find this concept in Plotinus’ writings, and his own statements about method point in other directions.
Eduard Zeller (active in the second half of the 19th century) is typically regarded as the first who gave a satisfying account of Plotinus’ philosophy as a whole. In this article, on the other hand, Zeller is seen as the one who finalised a tradition initiated in the 18th century. Very few Plotinus scholars have examined the interpretative development prior to Zeller. Schiavone (1952) and Bonetti (1971), for instance, have given little attention to Brucker’s introduction of the concept system of philosophy. The present analysis, then, has value to an understanding of Plotinus’ Enneads. It is also valuable in order to understand why 15th-, 16th- and 17th-century interpretations of Plotinus appear alien to the modern reader; the analysis may even serve to make some sense of the hermeneutics employed by Renaissance Platonists and commentators, who are often eclipsed from the tradition of Platonism