Letters 94.69

It is a great part of health to have forsaken the counsellors of madness and to have fled far from a companionship that is mutually baneful.

That you may know the truth of my remark, see how different is each individual’s life before the public from that of his inner self. A quiet life does not of itself give lessons in upright conduct; the countryside does not of itself teach plain living; no, but when witnesses and onlookers are removed, faults which ripen in publicity and display sink into the background.

Seneca, Letters to Lucilius 94.69, translated by Richard Mott Gummere