In a recent article, George Boys-Stones (2018b) offered an interesting definition of the Imperial Platonist conception of authority. According to him, contrary to the members of the other Hellenistic schools, the Middle Platonists do not aim to acquire a sum of propositional knowledge to be preserved within the school. Plato’s authority was for them not that of a founder of a school, but that of a man who had seen the intelligible Forms and discovered a truth to which all subsequent Platonists aspired. According to Boys-Stones, this conception of authority goes hand in hand with a certain epistemological perspective, the traces of which we can find in the fragments of Numenius, most notably in how he thinks of the relation between the second and the third God (fr. 11 des Places). The perspective of this paper is slightly different.

From the very early treatises, Plotinus highlights that the perception of harmonies and rhythms could lead up to the grasp of intelligible harmony. While Plotinus abandons the link between music and astronomy, distinguishing himself from the general reading of Plato developed in the imperial era, he stresses the psychagogical dimension of music. On the one hand, he simplifies the analyses devoted to music as a preparatory discipline, but on the other, he draws upon examples from the arts of rhythm (namely dance and music) to illustrate key aspects of his cosmology and of causal processes. After reviewing the place of music in Plotinus’ metaphysical organization, this chapter examines the use Plotinus makes of images related to music, dance and rhythm to exemplify different causal relationships. It concludes with an analysis of the meaning of a hapax, the adjective arrhythmistos taken from Aristotelian doxography and initially associated with the primordial indetermination of matter. These considerations lead to the conclusion that, in the Enneads, the concept of rhythmos goes beyond the field of musical arts and denotes the dynamic productivity of intelligible realities.