But out of very many evils which he has inflicted on the Commonwealth, there has emerged this much good: the Roman people has now learned how much to trust each man, on whom to rely, of whom to beware.

[Sed ex plurimis malis quae ab illo rei publicae sunt inusta hoc tamen boni est quod didicit iam populus Romanus quantum cuique crederet, quibus se committeret, a quibus caveret.]

Marcus Tullius Cicero (106-43 BC) Roman orator, statesman, philosopher

Philippics [Philippicae; Antonian Orations], No. 2, ch. 46 / sec. 117 (2.46/2.117) (44-10-24 BC) [tr. Ker (Loeb) (1926)]
    (Source)

Speaking of Julius Caesar and public awareness of who backed or opposed him.

(Source (Latin)). Other translations:

But amid all the many evils which he has branded on the state, this good result there is, that the Roman people has now learned how far each man deserves its confidence, to whom it may entrust itself, of whom it should beware.
[tr. King (1877)]

But from the many evils which by him have been burned into the republic, there is still this good, that the Roman people has now learned how much to believe every one, to whom to trust itself, and against whom to guard.
[tr. Yonge (1903)]

But out of the many evils which Caesar inflicted on our country, there has come one good thing: the Roman people have now learned how far they can trust each person, whom they can rely on, and whom they should beware of.
[tr. Berry (2006)]

But, from the many evils which he branded on the Republic, this much that was good still came about: that the Roman people learnt how much to trust anyone, to whom they could entrust themselves and against whom they should be on their guard.
[tr. McElduff (2011)]