Plato, Plotinus, and the Chaldean Oracles on “Pure Soul” In VP 23.3–4, Porphyry reports that Plotinus kept his soul pure. Although the remark has the air of a pupil’s rhetorical embellishment of his teacher, a closer examination of the use of the concept of “pure soul” in Plato, Plotinus, and the Chaldean Oracles reveals its ontological origin and dispels the air of hagiographical simplicity from it. The goal of this paper is to investigate the ontological root of the term and to demonstrate the confluence of ontology and soteriology in the conception, as presented in the Phaedo, the Enneads, and the Chaldean Oracles. “Likeness to god” (ὁµοίωσις θεῷ, Theaet. 176a–b) is Plato’s prescription for the meaning of man’s life. In the Phaedo (65e–70a), he envisions katharsis as the means for attaining this purpose. As a result, one of the main themes of the dialogue is soul’s liberation from the body. In this line of reasoning, Plato very often uses vocabulary related to καθαρός to convey the idea of soul’s separation from the body. There is nothing surprising in this usage. The surprising element, however, is that τὸ καθαρόν in Phaed. (79d2, 80d6, 82b11, to list a few) does not denote, as expected, the final result of the soul’s separation from the body, but the original starting point of soul’s descent into the body. Τὸ καθαρόν, in other words, does not mean “purified from the body” but “absolute existence” or “existence without body.” I will argue that, in the Phaedo, this ontological meaning is primary and the soteriological meaning is only secondary to it. Plotinus, in his turn, also emphasizes the ontological meaning of “pure soul.” He uses the expression when he talks about “the first principle of soul” (Enn. II.3.9), soul in the intelligible realm (Enn. III.3.5.17–18), Intellect “in pure light and pure radiance” (Enn. III.8.11.26–29), the individual soul without body (Enn. IV.3.24.22–29), and above all the unifying existence of all souls before they become attached to a particular man and descend into a particular body (Enn. VI.4.14.18–32). The proposed examination will show that Plotinus places the same ontological emphasis on the term as Plato does in the Phaedo. In the Chaldean Oracles, however, we find the emphasis shifting from the ontological to the soteriological meaning of καθαρός (fr. 213). Paradoxically, then, Porphyry’s statement about Plotinus’ “pure soul” rings more true with the Chaldean than the Platonic and even Plotinian conception of “pure.”