By Msgr. Charles Pope, Catholic Education Resource Center - Given improper intentions or excess or misguided application, vengeance can indeed be a sin and a vice. However, as we read in Scripture, "Vengeance is mine, says the Lord, I will repay" (Rom 12:19). Or again, as St. Thomas Aquinas notes, the scriptures assure: "Will not God avenge His elect who cry to Him day and night?" (Lk 18:7). But if vengeance is only a vice and an evil, then how can God attribute vengeance to himself? God does nothing evil. Hence in vengeance there is the possibility of virtue and that which is good. According to St. Thomas, vengeance is a special virtue in service of justice.