Lucretius, De Rerum Natura 3.41-58
“For men often claim that disease and a life
of a bad reputation should be feared more than Tartaros.
And they claim they know that the nature of the soul is like blood
Or even air, if that fits their current desire.
And they claim that they do not need our arguments.
But what follows will make you see these things as a matter of boasting
rather than because the matter itself has been proved.
The same men, out of their homeland and in a long exile
From the sight of others, charged with some foul crime,
live as they do, even afflicted with all possible troubles.
But, still, wherever they go the outcasts minister to their ancestors
and slaughter dark cattle and make their offerings
to the departed ghosts and when things get worse
they focus more sharply on religion.
For this reason it is better to examine a man in doubt or danger:
Adverse circumstances make it easier to know who a man is,
for then true words finally rise from his deepest heart;
when the mask is removed, the thing itself remains.”
nam quod saepe homines morbos magis esse timendos
infamemque ferunt vitam quam Tartara leti
et se scire animi naturam sanguinis esse,
aut etiam venti, si fert ita forte voluntas,
nec prosum quicquam nostrae rationis egere,
hinc licet advertas animum magis omnia laudis
iactari causa quam quod res ipsa probetur.
extorres idem patria longeque fugati
conspectu ex hominum, foedati crimine turpi,
omnibus aerumnis adfecti denique vivunt,
et quo cumque tamen miseri venere parentant
et nigras mactant pecudes et manibus divis
inferias mittunt multoque in rebus acerbis
acrius advertunt animos ad religionem.
quo magis in dubiis hominem spectare periclis
convenit adversisque in rebus noscere qui sit;
nam verae voces tum demum pectore ab imo
eliciuntur [et] eripitur persona manet res.
There are always other methods too:
Carm. Conv. 6
“What kind of man each person is
I wish I could know by opening his chest and then
once I have looked at his mind and after closing it again
To recognize a dear friend by his guileless thought”
εἴθ’ ἐξῆν ὁποῖός τις ἦν ἕκαστος
τὸ στῆθος διελόντ’, ἔπειτα τὸν νοῦν
ἐσιδόντα, κλείσαντα πάλιν,
ἄνδρα φίλον νομίζειν ἀδόλωι φρενί.