Encounters between strangers in the desert, while rare, were occasions of mutual suspicions, and marked by initial preparations on both sides for an incident that might prove either cordial or warlike. (1.4)
Francis cannot tell upon seeing the stranger whether or not their encounter will prove "cordial or warlike." It's like he's trying to determine if he'll meet a fellow human being or a beast in human's skin. Been there, buddy.
So it was that, after the Deluge, the Fallout, the plagues, the madness, the confusion of tongues, the rage, there began the bloodletting of the Simplification, when remnants of mankind had torn other remnants limb from limb, […]. (6.13)
Violence leads to vengeance, and one primitive act leads to another. And on and on.
The robber tossed the papers on the ground. "I'll wrestle you for them," he offered sportingly. "Those against my blade." (10.54)
Francis attempts to reason with the robber, but the robber does not have the same values as Francis. He only understands the base laws of nature, and that means the stronger character gets what the stronger character wants. And it's just best not to be weak.
They advanced to within ten yards of Francis before a pebble rattled. The monk was murmuring the third Ave of the Fourth Glorious Mystery of the rosary when he happened to look around. The arrow hit him squarely between the eyes. "Eat! Eat! Eat!" the Pope's child cried. (11.81-83)
This scene reads like a grotesque re-imagining of some NatGeo special on predators and prey. Only the lions are mutants, and the gazelle is Brother Francis.
Dom Paulo felt the blackness beginning to gather. After twelve centuries, a little hope had come into the world—and then came an illiterate prince to ride roughshod over it with a barbarian horde and… (17.22)
In his book The Better Angels of Our Nature, Steven Pinker argues that "government, literacy, trade, and cosmopolitanism" have resulted in a sharp decrease in violence in the modern world (source). A Canticle for Leibowitz basically argues the opposite.
"And how will this come to pass?" [Thon Taddeo] paused and lowered his voice. "In the same way all change comes to pass, I fear. And I am sorry it is so. It will come to pass by violence and upheaval, by flame and by fury, for no change comes calmly over the world." (20.127)
What do you think: is Thon Taddeo's belief realistic or pessimistic? Can we learn to change without violence and upheaval, or will our primitive sides always prevail?
The impulse had sent [the Poet] leaping from the embankment to tackle the cavalry officer in the saddle and stab the fellow three times with his own belt-knife before the two of them toppled to the ground. (23.4)
Didn't think the Poet had it in him, did you? And let's not forget that Zerchi will give Dr. Cors a wicked haymaker later. Seems no one in this novel can escape their primitive impulses.
When the world was in darkness and wretchedness, it could believe in perfection and yearn for it. But when the world became bright with reason and riches, it began to sense the narrowness of the needle's eye, and that rankled for a world no longer willing to believe or yearn. Well, they were going to destroy it again, were they— (26.59)
You'd think that as we improve our lives, our primitive natures would lessen. Maybe even disappear. But the book wonders if the opposite isn't true.
"What's to be believed? Or does it matter at all? When mass murder's been answered with mass murder, rape with rape, hate with hate, there's no longer meaning in asking whose ax is the bloodier. Evil, on evil, piled on evil." (26.9)
Here, we return to the idea of violence leading to more violence. This time, it comes packaged with the notion of justice, but Father Zerchi questions the validity of responding to one primitive act with another. Do two wrongs ever make a right? (Probably not, unless you're in the business of making axes.)
"Two cities have died, but it is to be remembered that neither side answered with a saturation attack. The Asian rulers contend that an eye was taken for an eye. Our government insists that the explosion in Itu Wan was taken for an eye." (28.39)
As Jesus said, "Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also" (Matthew 5:38-39). Or as Gandhi said, "An eye for an eye only ends up making the whole world blind" (source). You can pick either Jesus or Gandhi, but we bet this wisdom is the closest A Canticle gets to countering humanity's more primitive tendencies.