Letters 47.17

“He is a slave.” His soul, however, may be that of a freeman. “He is a slave.” But shall that stand in his way? Show me a man who is not a slave; one is a slave to lust, another to greed, another to ambition, and all men are slaves to fear. I will name you an ex-consul who is slave to an old hag, a millionaire who is slave to a serving-maid; I will show you youths of the noblest birth in serfdom to pantomime players! No servitude is more disgraceful than that which is self-imposed.

You should therefore not be deterred by these finicky persons from showing yourself to your slaves as an affable person and not proudly superior to them; they ought to respect you rather than fear you.

Seneca, Letters to Lucilius 47.17, translated by Richard Mott Gummere