Moral Letters to Lucilius Section 3

Malus omnia in malum vertit, etiam quae cum specie optimi venerant; rectus atque integer corrigit prava fortunae et dura atque aspera ferendi scientia mollit, idemque et secunda grate excipit modesteque et adversa constanter ac fortiter. Qui licet prudens sit, licet exacto faciat cuncta iudicio, licet nihil supra vires suas temptet, non continget illi bonum illud integrum et extra minas positum, nisi certus adversus incerta est.

Pour le méchant rien qui ne tourne en mal, même ce qui lui venait sous l’apparence du plus grand bien ; l’âme droite et saine redresse les torts de la Fortune, adoucit ses plus vives rigueurs par l’art de les supporter, reconnaissante et modeste dans le succès, courageuse et ferme dans la disgrâce.

A bad man makes everything bad - even things which had come with the appearance of what is best; but the upright and honest man corrects the wrongs of Fortune, and softens hardship and bitterness because he knows how to endure them; he likewise accepts prosperity with appreciation and moderation, and stands up against trouble with steadiness and courage. Though a man be prudent, though he conduct all his interests with well-balanced judgment, though he attempt nothing beyond his strength, he will not attain the Good which is unalloyed and beyond the reach of threats, unless he is sure in dealing with that which is unsure.