Seneca, Moral Epistles 103.1-3
“Why do you look around for those things that just might happen to you but also might not happen at all? I am talking about a fire, building damage, and the other kinds of things that happen to us but aren’t done to us. Instead, look out for those things, avoid those things that follow us, that clutch at us.
Accidents are relatively rare, even if they are serious: a shipwreck, a car crash. But there’s daily danger for people from people. Set yourself against this–keep your eyes open for this. There’s no danger so common, nothing so persistent, nothing so endearing on the surface. A storm at least threatens before it strikes; foundations creak before they crumble; smoke presages a fire–yet peril from another person and it is as carefully hidden as it kept nearby.
You’re screwing up if you trust the expressions of the people you meet. They have human faces but the hearts of beasts, except the danger of beasts comes from your first meeting, and they don’t seek those they have passed by. They only do harm when need forces it: they are compelled to fight by hunger or fear. But people enjoy destroying other people.”
Quid ista circumspicis, quae tibi possunt fortasse evenire, sed possunt et non evenire? Incendium dico, ruinam, alia, quae nobis incidunt, non insidiantur; illa potius vide, illa devita, quae nos observant, quae captant. Rariores sunt casus, etiam si graves, naufragium facere, vehiculo everti; ab homine homini cotidianum periculum. Adversus hoc te expedi, hoc intentis oculis intuere. Nullum est malum frequentius, nullum pertinacius, nullum blandius. Ac tempestas minatur antequam surgat, crepant aedificia antequam corruant, praenuntiatfumus incendium; subita est ex homine pernicies et eo diligentius tegitur, quo propius accedit.
Erras, si istorum tibi qui occurrunt vultibus credis; hominum effigies habent, animos ferarum, nisi quod illarum perniciosus est primus incursus; quos transiere, non quaerunt. Numquam enim illas ad nocendum nisi necessitas incitat; aut fame aut timore coguntur ad pugnam; homini perdere hominem libet.