Meditations 8.51

Neither in thy actions be sluggish nor in thy conversation without method, nor wandering in thy thoughts, nor let there be in thy soul inward contention nor external effusion, nor in life be so busy as to have no leisure.

Suppose that men kill thee, cut thee in pieces, curse thee. What then can these things do to prevent thy mind from remaining pure, wise, sober, just? For instance, if a man should stand by a limpid pure spring, and curse it, the spring never ceases sending up potable water; and if he should cast clay into it or filth, it will speedily disperse them and wash them out, and will not be at all polluted. How then shalt thou possess a perpetual fountain [and not a mere well]? By forming thyself hourly to freedom conjoined with contentment, simplicity, and modesty.

Marcus Aurelius, Meditations 8.51, translated by George Long

Be not dilatory in doing, nor confused in conversation, nor vague in thought; let not thy soul be wholly concentred in itself nor uncontrollably agitated; leave thyself leisure in thy life.

They kill us, they cut us limit from limb, they hunt us with execrations! How does that prevent thy mind being still pure, sane, sober, just? Imagine a man to stand by a crystal-clear spring of sweet water, and to rail at it; yet it fails not to bubble up with wholesome water. Throw in mud or even filth and it will quickly winnow them away and purge itself of them and take never a stain. How then possess thyself of a living fountain and no mere well? By guiding thyself carefully every hour into freedom with kindliness, simplicity, and modesty.

Marcus Aurelius, Meditations 8.51, translated by C. R. Haines