Gregory the Great, The Book of Pastoral Rule II.9: That the ruler ought to be careful to understand how commonly vices pass themselves off as virtues

That the ruler ought to be careful to understand how commonly vices pass themselves off as virtues.

The ruler also ought to understand how commonly vices pass themselves off as virtues. For often niggardliness palliates itself under the name of frugality, and on the other hand prodigality hides itself under the appellation of liberality. Often inordinate laxity is believed to be loving-kindness, and unbridled wrath is accounted the virtue of spiritual zeal. Often precipitate action is taken for the efficacy of promptness, and tardiness for the deliberation of seriousness. Whence it is necessary for the ruler of souls to distinguish with vigilant care between virtues and vices, lest either niggardliness get possession of his heart while he exults in seeming frugal in expenditure; or, while anything is prodigally wasted, he glory in being as it were compassionately liberal; or in remitting what he ought to have smitten he draw on those that are under him to eternal punishment; or in mercilessly smiting an offence he himself offend more grievously; or by immaturely anticipating mar what might have been done properly and gravely; or by putting off the merit of a good action change it to something worse.