Of the value of the lust of the flesh against the spirit in our case.
To begin with, because it is an immediate reproof of our sloth and carelessness, and like some energetic schoolmaster who never allows us to deviate from the line of strict discipline, and if our carelessness has ever so little exceeded the limits of due gravity which become it, it immediately excites us by the stimulus of desire, and chides us and recalls us to due moderation. Secondly, because, in the matter of chastity and perfect purity, when by Gods grace we see that we have been for some time kept from carnal pollution, in order that we may not imagine that we can no longer be disturbed by the motions of the flesh and thereby be elated and puffed up in our secret hearts as if we no longer bore about the corruption of the flesh, it humbles and checks us, and reminds us by its pricks that we are but men. 1304 For as we ordinarily fall without much thought into other kinds of sins and those worse and more harmful, and are not so easily ashamed of committing them, so in this particular one the conscience is especially humbled, and by means of this illusion it is stung by the recollection of passions that have been neglected, as it sees clearly that it is rendered unclean by natural emotions, of which it knew nothing while it was still more unclean through spiritual sins; and so coming back at once to the cure of its former sluggishness, it is warned both that it ought not to trust in the attainments of purity in the past, which it sees to be lost by ever so small a falling away from the Lord, and also that it cannot attain the gift of this purity except by Gods grace alone, since actual experience somehow or other teaches us that if we are anxious to reach abiding perfection of heart we must constantly endeavour to obtain the virtue of humility.
Suo nos rursum quamvis quieto ac simplici visitans fluxu.