Meditations 4.18

How much trouble he avoids who does not look to see what his neighbor says or does or thinks, but only to what he does himself, that it may be just and pure; or, as Agathon says, look not round at the depraved morals of others, but run straight along the line without deviating from it.

Marcus Aurelius, Meditations 4.18, translated by George Long

What richness of leisure doth he gain who has no eye for his neighbour's words or deeds or thoughts, but only for his own doings, that they be just and righteous! Verily it is not for the good man to peer about into the blackness of another's heart, but to 'run straight for the goal with never a glance aside.'

Marcus Aurelius, Meditations 4.18, translated by C. R. Haines