Wow! Such penatrating insight! The slaughter was the result of the "custom of war." Brilliant! What a formidable mind!
I felt it my duty to, lest you take from that small fragment that Augustine was a bore, to provide you with the full quotation:
All the spoiling, then, which Rome was exposed to in the recent calamity--all the slaughter, plundering, burning, and misery--was the result of the custom of war. But what was novel, was that savage barbarians showed themselves in so gentle a guise, that the largest churches were chosen and set apart for the purpose of being filled with the people to whom quarter was given, and that in them none were slain, from them none forcibly dragged; that into them many were led by their relenting enemies to be set at liberty, and that from them none were led into slavery by merciless foes. Whoever does not see that this is to be attributed to the name of Christ, and to the Christian temper, is blind; whoever sees this, and gives no praise, is ungrateful; whoever hinders any one from praising it, is mad. Far be it from any prudent man to impute this clemency to the barbarians. Their fierce and bloody minds were awed, and bridled, and marvellously tempered by Him who so long before said by His prophet, "I will visit their transgression with the rod, and their iniquities with stripes; nevertheless my loving-kindness will I not utterly take from them." -City of God Book I