Abstract

The Treatise On Numbers develops a typical Plotinian inquiry about oneness and intelligible plurality, in which the analysis is based on the problem of the infinite inside the intelligible realm, as it seems to be presented in the socalled generation of numbers in Plato's Parmenides, where numbers are linked to Being, identified by Plotinus with the hypostasis of Intellect, and produce a process of unlimited division. In order to avoid this interpretation, Plotinus finds in other Plato's dialogues the proof that number is an eidetic nature, encompassing all the intelligible entities, so that the infinite has to be interpreted as what is produced by calculus. Other arguments are rather depending on the model of the Old Academy, concerning the relationship between forms and numbers: Plotinus wonders if numbers come ontologically before forms and indeed he states right this position. Other aspects of Plotinus' investigation, which can be traced back to the Old Academy, are the distinction between two kinds of numbers and the doctrine of the unified number. This model of number, quite ambiguous, may be identified with the indefinite dyad, even though the former has to be conceived, differently from that of Old Academy, within a mono-polar framework, according to which the sole principle is the One.