XV. I would then say this. Since some things are within and some without the soul, and if the soul make a good use of them, they also are reputed good, but if a bad, bad;—whether does He who commands us to alienate our possessions repudiate those things, after the removal of which the passions still remain, or those rather, on the removal of which wealth even becomes beneficial? If therefore he who casts away worldly wealth can still be rich in the passions, even though the material [for their gratification] is absent,—for the disposition produces its own effects, and strangles the reason, and presses it down and inflames it with its inbred lusts,—it is then of no advantage to him to be poor in purse while he is rich in passions. For it is not what ought to be cast away that he has cast away, but what is indifferent; and he has deprived himself of what is serviceable, but set on fire the innate fuel of evil through want of the external means [of gratification]. We must therefore renounce those possessions that are injurious, not those that are capable of being serviceable, if one knows the right use of them. And what is managed with wisdom, and sobriety, and piety, is profitable; and what is hurtful must be cast away. But things external hurt not. So then the Lord introduces the use of external things, bidding us put away not the means of subsistence, but what uses them badly. And these are the infirmities and passions of the soul.