Ataraxia

Tranquillity. Freedom from disturbance.

The Hellenistic schools — Epicurean, Stoic, Skeptic — agree that the goal of philosophy is psychological. Epicurus's ataraxia is undisturbedness, the state of one whose desires are tuned to what is actually available. The Stoics call something similar apatheia. The Skeptics arrive at it through suspension of judgment. All three are recipes for an ancient cousin of mindfulness.