By remembering then that I am a part of such a whole, I shall be content with everything that happens. And inasmuch as I am in a manner intimately related to the parts which are of the same kind with myself, I shall do nothing unsocial, but I shall rather direct myself to the things which are of the same kind with myself, and I shall turn all my efforts to the common interest, and divert them from the contrary.

X, 6 - Meditations (c. 161–180 CE) - Book X