WIST

In truth, prosperity tries the souls of even the wise; how then should men of depraved character like these make a moderate use of victory?

[Quippe secundae res sapientium animos fatigant, ne illi corruptis moribus victoriae temperarent.]

Sallust (c. 86-35 BC) Roman historian and politician [Gaius Sallustius Crispus]
Bellum Catilinae [The War of Cateline; The Conspiracy of Catiline], ch. 11, sent. 8 [tr. Rolfe (1931)]
    (Source)

Alt. trans.:

• "A series of prosperity is often too much even for the wisest and best disposed: that men corrupted should make a temperate use of their victory could not be expected." [tr. Murphy (1807)]
• "For success unhinges the minds even of wise men; how then should they who were so depraved use their victory with moderation?" [tr. Rose (1831)]
• "For success tries the minds of wise men, much less could they, when their morals were corrupted, use their victory with moderation." [Source (1841)]
• "Success unsettles the principles even of the wise, and scarcely would those of debauched habits use victory with moderation." [tr. Watson (1867)]
• "Since even the wise have their temper tried by prosperity, much less could men of this abandoned character use their success with moderation." [tr. Pollard (1882)]
• "Successful situations overwhelm the minds even of the wise; still less wouild those men of corrupt morals moderate their victory." [tr. Woodman (2007)]