According to Augustine, what happens to vices when they are not residing in a human soul? Can you find any flaws in his analogy of evil with disease? (Remember: Augustine could not have known about germs and viruses!)
By the Trinity, (1) thus supremely and equally and unchangeably good, all things were created; and these are not supremely equally and unchangeably good, but yet they are good, even taken separately. Taken as a whole, however, they are very good, because their ensemble constitutes the universe in all its wonderful order and beauty.
And in the universe, even that which is called evil, when it is regulated and put in its own
place, only enhances our admiration of the good; for we enjoy and value the good more
when we compare it with the evil. For the almighty God, who, as even the heathen
acknowledge, has supreme power over all things, being Himself supremely good, would
never permit the existence of anything 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 mean 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 from the body and dwell elsewhere: they
altogether cease to exist; for the wound or disease is not a substance, (2) but a defect in the
fleshly substance--the flesh itself being a substance, and therefore something good, of which
those evils--that is, privations of the good which we call health--are accidents. (3) Just in the
same way, what are called vices in the soul are nothing but privations of natural good. And
when they are not transferred elsewhere: when they cease to exist in the healthy soul, they
cannot exist anywhere else.
Translated by Marcus Dods (1876).
(2) Substance" is a technical term, meaning that which endures through time even though it may undergo certain changes of quality or of state. The substance is thus more real than are its changeable features.
(3) "Accident," too, is a technical term, meaning not "happening by chance" but rather "those qualities or states of a thing which might have been different than they are." Thus accidents can only exist if there is something more real of which they can be the features.