Meditations 6.11

When thou hast been compelled by circumstances to be disturbed in a manner, quickly return to thyself, and do not continue out of tune longer than the compulsion lasts; for thou wilt have more mastery over the harmony by continually recurring to it.

Marcus Aurelius, Meditations 6.11, translated by George Long

When forced, as it seems, by thine environment to be utterly disquieted, return with all speed into thy self, staying in discord no longer than thou must. By constant recurrence to the harmony, thou wilt gain more command over it.

Marcus Aurelius, Meditations 6.11, translated by C. R. Haines