Eraclitus was a Platonian who possessed psychokinetic powers. The product of a mass eugenics program on the planet Sahndara, he was bred for contemplation, self-reliance, and longevity, along with 37 others. Before his planet's star went nova, he and the other Platonians resettled on Earth where they were exposed to the Greek civilization. When this civilization died, they moved on to Platonius where they founded their republic.

In 2268, he participated in a series of "games" designed to humiliate the USS Enterprise crew members and entertain the Platonians. (TOS: "Plato's Stepchildren")

Eraclitus was played by Ted Scott.