Abstract

This chapter traces the historical and philosophical background of the concept of number from the Presocratics’ understanding of One and Many through Plato’s concepts of Limit and Unlimited, and Aristotle’s debate on the nature of number with Speusippus and Xenocrates, to the Neopythagoreans and Plotinus. Next, it examines the main difficulties with the concept of number in Plotinus: the unsystematic presentation of the concept in the Enneads, the lack of scholarly interest, and the brevity of Plotinus’ treatment of the subject. At the end, this examination focuses on the presentation of the concept in Ennead VI.6, the treatise On Numbers. From a bird’s-eye view, the subject of multiplicity begins and ends the thematic composition of the treatise. As multiplicity unfolds from the One and enfolds to the One, so does the composition of the treatise unfold and enfold in nesting circles, moving away from and yet turning toward their center. The concentric composition of VI.6 conveys non-discursively the higher ontological presence of number in the intelligible realm and iconically sketches the spherical figure of the universe.