Book IX · 6
Thy present opinion founded on understanding, and thy present conduct directed to social good, and thy present disposition of contentment with everything which happens—that is enough.
The present assumption rightly apprehended, the present act socially enacted, the present disposition satisfied with all that befalls it from the Cause external to it—these will suffice.
Marcus Aurelius, Meditations IX.6. Translated by George Long (1862). The Stoic Library.