That Even the Fierceness of War and All the Disquietude of Men Make Towards This One End of Peace, Which Every Nature Desires
He, then, who prefers what is right to what is wrong, and what is well-ordered to what is perverted, sees that the peace of unjust men is not worthy to be called peace in comparison with the peace of the just. And yet even what is perverted must of necessity be in harmony with, and in dependence on, and in some part of the order of things, for otherwise it would have no existence at all. Suppose a man hangs with his head downwards, this is certainly a perverted attitude of body and arrangement of its members; for that which nature requires to be above is beneath, and vice versâ.
This perversity disturbs the peace of the body, and is therefore painful. Nevertheless the spirit is at peace with its body, and labors for its preservation, and hence the suffering; but if it is banished from the body by its pains, then, so long as the bodily framework holds together, there is in the remains a kind of peace among the members, and hence the body remains suspended. And inasmuch as the earthly body tends towards the earth, and rests on the bond by which it is suspended, it tends thus to its natural peace, and the voice of its own weight demands a place for it to rest; and though now lifeless and without feeling, it does not fall from the peace that is natural to its place in creation, whether it already has it, or is tending towards it.
For if you apply embalming preparations to prevent the bodily frame from mouldering and dissolving, a kind of peace still unites part to part, and keeps the whole body in a suitable place on the earth—in other words, in a place that is at peace with the body. If, on the other hand, the body receive no such care, but be left to the natural course, it is disturbed by exhalations that do not harmonize with one another, and that offend our senses; for it is this which is perceived in putrefaction until it is assimilated to the elements of the world, and particle by particle enters into peace with them.
Yet throughout this process the laws of the most high Creator and Governor are strictly observed, for it is by Him the peace of the universe is administered. For although minute animals are produced from the carcass of a larger animal, all these little atoms, by the law of the same Creator, serve the animals they belong to in peace. And although the flesh of dead animals be eaten by others, no matter where it be carried, nor what it be brought into contact with, nor what it be converted and changed into, it still is ruled by the same laws which pervade all things for the conservation of every mortal race, and which bring things that fit one another into harmony.
Source: City of God (New Advent)