Abstract

This article delves into two triadic structures associated with the doctrine περὶ ψυχῆς, initially formulated by Iamblichus and later embraced by two of his successors, Proclus and Hermias of Alexandria. The goal is to provide two distinct analytical perspectives. In the first section, the article presents a precise classification of human souls, categorizing them as first‑class souls, second‑class souls, and third‑class souls. This classification will be referred to as the “triad of souls”. Within this context, particular emphasis is placed on the first‑class souls, which Iamblichus, in his work De anima, describes as “pure and perfect souls.” These souls possess a unique ontological status, making them a central focus throughout the text. In the second part, we outline what we call the “upper mereology” of the soul, focusing on the three “parts”, “aspects”, or “components” of the human soul, namely διάνοια, νοερόν, ἕν. This forms a triadic structure that we refer to as the “triad within the souls”. Finally, considering the discussions on the two Neoplatonic triads, the last part of the text introduces Plato’s “triad within the souls”, which comprises λογιστικόν, θυμοειδές, ἐπιθυμητικόν. This serves to demonstrate how Iamblichus and the later Neoplatonists approached and incorporated it, yielding original insights within their doctrine of the triad of souls.