A Treatise on the Spirit and the Letter 8
8 Romans Interprets Corinthians PL 44, 204
Attend, then, carefully, to the apostle while in his Epistle to the Romans he explains and clearly enough shows that what he wrote to the Corinthians, “The letter killeth, but the spirit giveth life,” must be understood in the sense which we have already indicated,—that the letter of the law, which teaches us not to commit sin, kills, if the life-giving spirit be absent, forasmuch as it causes sin to be known rather than avoided, and therefore to be increased rather than diminished, because to an evil concupiscense there is now added the transgression of the law.
Attende igitur Apostolum ad Romanos explicantem, satisque monstrantem quod scripsit ad Corinthios, Littera occidit, spiritus autem vivificat, sic magis accipiendum, quemadmodum supra diximus; quoniam legis littera quae docet non esse peccandum, si spiritus vivificans desit, occidit: sciri enim facit peccatum potius quam caveri, et ideo magis augeri quam minui, quia malae concupiscentiae etiam praevaricatio legis accedit.