Tradition

Middle Platonists, possibly Hindus → Ammonius Saccas (died c. AD 265) an apostate → Plotinus (c. 205 – c. 270) of Egypt → Porphyry (c. 233–c. 309) of Syria → Iamblichus (c. 245 – c. 325) of Syria.

Later, Hypatia (c. 360 – 415) of Egypt who was burned by Christians, Proclus Lycaeus (February 8, 412 – April 17, 485) of Lycia in Anatolia, Roman Emperor Julian (331/332 – 26 June 363)) the apostate and his friend Sallustius.

Current utility

Platonism is particularly useful in the case of sundered traditions which have lost their esoteric or wisdom components, without which practitioners are prey to mythic literalism and problems of discernment. The more intact your tradition, the less need there is for Platonism. The utility for intact, continuous traditions would be rather in relating to other traditions, where Platonism can provide a non-reductionist and non-intrusive model for engagement.