Sometimes with the devil’s help, as magicians and witches do; sometimes through deceptions, potions, poisons, stratagems, duels and wars, we hack and hew as though we were “born for mutual destruction,” like Cadmus’s soldiers, born to kill one another. It is commonplace to read of a hundred or two hundred thousand men killed in a battle. Besides these are all kinds of torture: bronze bulls, racks, wheels, strappadoes, guns, devices and so on. “For one human body there are more tortures than limbs.” We have invented more instruments of torture than the body has separate members, as Cyprian aptly observes.

To come nearer still: through their offences, lack of judgement and intemperance, our own parents are our mortal enemies. “The fathers have eaten sour grapes, and the children’s teeth are set on edge.” They often cause our suffering, passing on hereditary diseases and inescapable infirmities. They torment us, and we in turn are ready to injure our descendants, “soon to produce a still more vicious generation.” As Paul foretold, the world’s last days are likely to be the worst. We are thus bad by nature, bad by birth, but far worse through our own contrivance, each person his own greatest enemy.

We often take pains to ruin ourselves, abusing God’s good gifts—health, wealth, strength, intelligence, learning, skill and memory—to bring about our own destruction. “Your destruction comes from yourself.” As Judas Maccabaeus killed Apollonius with Apollonius’s own weapons, we arm ourselves for our own overthrow, using reason, skill and judgement—all that should help us—as instruments of our ruin.

Hector gave Ajax a sword which helped and defended him as long as he fought his enemies; but after he began to harm innocent creatures with it, it turned against his own innocent entrails. Those excellent resources God has given us, if well employed, cannot fail to benefit us greatly; but if misused, they ruin and destroy us. Through our lack of judgement and weakness, that is what they commonly do: we have all too many examples.

St Augustine acknowledged this of himself in his humble Confessions: quickness of mind, memory and eloquence were God’s good gifts, but he did not use them for God’s glory. If you want to know precisely how and by what means we do this, consult physicians. They will tell you that it comes from mismanaging one or another of the six “non-natural” things, which I shall discuss more fully later. These are the causes of our infirmities: our overeating and drunkenness, our immoderate, insatiable lust and our monstrous excess.

“More by gluttony than by the sword” is a true saying: the table consumes more lives than the sword. It is our intemperance that brings so many different incurable diseases upon us, hastens old age, disrupts our bodily constitution and brings sudden death. And last of all, what torments us most is our own folly, madness—“those whom Jupiter destroys, he drives mad”; God permits it by withdrawing his assisting grace—weakness, lack of self-control, and readiness to yield to every sort of desire, giving way to every passion and disturbance of the mind. By these means we transform ourselves and degenerate into beasts.

All this the prince of poets observed in Agamemnon: when content and able to govern his passions, he was “like Jupiter in face and eyes”—Jupiter in appearance, Mars in courage, Pallas in wisdom, another god. But when he grew angry he was a lion, a tiger, a dog and so on: no sign or likeness of Jupiter appeared in him.

So we, as long as we are governed by reason, restrain our disordered appetites and conform to God’s word, are like so many living saints. But if we give free rein to lust, anger, ambition and pride, and follow our own ways, we degenerate into beasts, transform ourselves, ruin our constitutions, provoke God to anger, and heap upon ourselves this disease of melancholy and every kind of incurable illness, as the just and deserved punishment of our sins.