Concerning the Nature of Good, Against the Manichæans 5
5 The Corrupted Nature of a More Excellent Order Sometimes Better Than an Inferior Nature Even Uncorrupted PL 42, 553
But it may happen, that a certain nature which has been ranked as more excellent by reason of natural measure and form, though corrupt, is even yet better than another incorrupt which has been ranked lower by reason of an inferior natural measure and form: as in the estimation of men, according to the quality which presents itself to view, corrupt gold is assuredly better than incorrupt silver, and corrupt silver than incorrupt lead; so also in more powerful spiritual natures a rational spirit even corrupted through an evil will is better than an irrational though incorrupt, and better is any spirit whatever even corrupt than any body whatever though incorrupt. For better is a nature which, when it is present in a body, furnishes it with life, than that to which life is furnished. But however corrupt may be the spirit of life that has been made, it can furnish life to a body, and hence, though corrupt, it is better than the body though incorrupt.
Natura excellentioris ordinis etiam corrupta melior interdum inferiore etiam incorrupta. Fieri autem potest, ut quaedam natura quae modo et specie naturali excellentius ordinata est, etiam corrupta melior sit adhuc quam est incorrupta altera, quae minore modo et specie naturali inferius ordinata est: sicut in hominum aestimatione, secundum qualitatem quae aspectibus adjacet, melius est utique corruptum aurum, quam incorruptum argentum; et melius est corruptum argentum, quam plumbum incorruptum. Sic et in naturis potentioribus atque spiritualibus melior est etiam corruptus per malam voluntatem spiritus rationalis, quam irrationalis incorruptus: et melior est quilibet spiritus etiam corruptus, quam corpus quodlibet incorruptum. Melior est enim natura, quae cum praesto est corpori, praebet ei vitam, quam illa cui vita praebetur. Quantumlibet autem corruptus sit spiritus vitae qui factus est, vitam praebere corpori potest: ac per hoc melior illo est, quamvis incorrupto, corruptus.