The Presence of Good and Evil

In qua etiam illud quod malum dicitur, bene ordinatum et loco suo positum, eminentius commendat bona, ut magis placeant et laudabiliora sint dum comparantur malis. Neque enim Deus omnipotens quod etiam infideles fatentur: Rerum cui summa potestas cum summe bonus sit, ullo modo sineret mali esse aliquid in operibus suis nisi usque adeo esset omnipotens et bonus ut bene faceret et de malo. Quid est autem aliud quod malum dicitur, nisi privatio boni? Nam sicut corporibus animalium nihil est aliud morbis et vulneribus affici quam sanitate privari, neque enim id agitur cum adhibetur curatio, ut mala ista quae inerant, id est morbi ac vulnera, recedant hinc et alibi sint, sed utique ut non sint; non enim ulla substantia, sed carnalis substantiae vitium est vulnus aut morbus, cum caro sit ipsa substantia, profecto aliquod bonum cui accidunt ista mala, id est privationes eius boni quod dicitur sanitas; ita et animorum quaecumque sunt vitia, naturalium sunt privationes bonorum: quae cum sanantur non aliquo transferuntur, sed ea quae ibi erant, nusquam erunt, quando in illa sanitate non erunt.  Sanctus Augustinus Hipponensis, Enchiridion de Fide, Spe et Charitate

Even that which is called evil, when it is ordered and put in its own place, increases our admiration of the good; for we take joy in and esteem the good more when we compare it with the evil. Almighty God, who, as even infidels acknowledge, has supreme power over all things, being Himself supremely powerful, would never permit evil among His works, if He were not so omnipotent and good that He can bring good even out of evil. For what is that which we call evil but the absence of good? In the bodies of animals, disease and wounds are nothing but the absence of health; for when a cure is effected, that does not mean that the evils which were present, namely the diseases and wounds, go away and dwell elsewhere, but rather they cease to exist, for the wound or disease is not a substance but a defect in corporeal substance, the flesh itself being a substance, and therefore something good, of which those evils, that is, the privations of the good which is called health, are accidents, so the defects of souls are nothing but privations of natural good. When they are cured the faults are not transferred elsewhere, for they cannot exist when they cease to exist in the healthy. Saint Augustine of Hippo, Enchiridion