ACC ~ Galatians 5 v17b

WHETHER THE SPIRIT SUCCEEDS. AUGUSTINE: The “flesh struggles against the spirit” yet does not subdue it, since the spirit also “struggles against the flesh.” Although that same law of sin holds something of the flesh as its prisoner and thereby resists the law of the mind it does not, however, reign in our body, mortal though it is, if our body does not voluntarily obey its desires. ON MARRIAGE AND CONCUPISCENCE 1.35.

AGAINST THE FLESH. JOHN CASSIAN: An inward war is being waged every day within us. The desires of the flesh and of the spirit are within one and the same person. The lust of the flesh rushes headlong into vice, delights in the worldly enjoyments that seem to satisfy. By contrast the opposed desire of the spirit is so eager to cleave entirely to spiritual pursuits that it in an exaggerated way chooses even to exclude the necessary uses of the flesh. By wishing to be so inseparably attached to spiritual things it refuses to take care of its own bodily fragility. CONFERENCES 4.11.2.

Gal