  On the whole, Proclus’ doctrine of first principles is a further development of Plotinus’ innovative interpretation of Platonic philosophy. With Plotinus, Proclus recognizes three fundamental levels of reality called ‘hypostases’ (or self-subsistent entities): One, Intellect, and Soul. However, following a concern of his predecessor Iamblichus for greater precision in the relationship and distinction between the One and Intellect, Proclus distinguishes between the intelligible Being (to noêton—what is the object of intellectual intuition) and the intellective (to noeron—what is intelligizing), and introduces between both, as an intermediary level, the noêton-noeron (what is being intelligized and intelligizing). These three ontological levels thus correspond to the triad of Being, Life, and Intellect, which already play an important role in Plotinus’ and Porphyry’s speculations about the procession or ‘emanation’ of the intelligible world from the One, without, however, being hypostasized. Since Zeller (influenced by Hegel) the application of the triadic structure to reality has been seen as the characteristic feature of Proclus’ system, but see Dodds 19632, pp. xxii and 220, on possible sources of the doctrine.