Meditations 11.16

As to living in the best way, this power is in the soul, if it be indifferent to things which are indifferent. And it will be indifferent, if it looks on each of these things separately and all together, and if it remembers that not one of them produces in us an opinion about itself, nor comes to us; but these things remain immovable, and it is we ourselves who produce the judgments about them, and, as we may say, write them in ourselves, it being in our power not to write them, and it being in our power, if perchance these judgments have imperceptibly got admission to our minds, to wipe them out; and if we remember also that such attention will only be for a short time, and then life will be at an end. Besides, what trouble is there at all in doing this? For if these things are according to nature, rejoice in them and they will be easy to thee: but if contrary to nature, seek what is conformable to thy own nature, and strive towards this, even if it bring no reputation; for every man is allowed to seek his own good.

Marcus Aurelius, Meditations 11.16, translated by George Long

Vested in the soul is the power of living ever the noblest of lives, let a man but be indifferent towards things indifferent. And he will be indifferent, if he examine every one of these things both in its component parts and as a whole, and bear in mind that none of them is the cause in us of any opinion about itself, nor obtrudes itself on us. They remain quiescent, and it is we who father these judgments about them and as it were inscribe them on our minds, though it lies with us not to inscribe them and, if they chance to steal in undetected, to erase them at once. Bear in mind too that we shall have but a little while to attend to such things and presently life will be at an end. But why complain of the perversity of things? If they are as Nature wills, delight in them and let them be no hardship to thee. If they contravene Nature, seek then what is in accord with thy nature and speed towards that, even though it be unpopular. For it is pardonable for every man to seek his own good.

Marcus Aurelius, Meditations 11.16, translated by C. R. Haines