Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 4

Chapter 4.—Of the Nature of Irrational and Lifeless Creatures, Which in Their Own Kind and Order Do Not Mar the Beauty of the Universe.

But it is ridiculous to condemn the faults of beasts and trees, and other such mortal and mutable things as are void of intelligence, sensation, or life, even though these faults should destroy their corruptible nature; for these creatures received, at their Creator’s will, an existence fitting them, by passing away and giving place to others, to secure that lowest form of beauty, the beauty of seasons, which in its own place is a requisite part of this world.  For things earthly were neither to be made equal to things heavenly, nor were they, though inferior, to be quite omitted from the universe.  Since, then, in those situations where such things are appropriate, some perish to make way for others that are born in their room, and the less succumb to the greater, and the things that are overcome are transformed into the quality of those that have the mastery, this is the appointed order of things transitory.  Of this order the beauty does not strike us, because by our mortal frailty we are so involved in a part of it, that we cannot perceive the whole, in which these fragments that offend us are harmonized with the most accurate fitness and beauty.  And therefore, where we are not so well able to perceive the wisdom of the Creator, we are very properly enjoined to believe it, lest in the vanity of human rashness we presume to find any fault with the work of so great an Artificer.  At the same time, if we attentively consider even these faults of earthly things, which are neither voluntary nor penal, they seem to illustrate the excellence of the natures themselves, which are all originated and created by God; for it is that which pleases us in this nature which we are displeased to see removed by the fault,—unless even the natures themselves displease men, as often happens when they become hurtful to them, and then men estimate them not by their nature, but by their utility; as in the case of those animals whose swarms scourged the pride of the Egyptians.  But in this way of estimating, they may find fault with the sun itself; for certain criminals or debtors are sentenced by the judges to be set in the sun.  Therefore it is not with respect to our convenience or discomfort, but with respect to their own nature, that the creatures are glorifying to their Artificer.  Thus even the nature of the eternal fire, penal though it be to the condemned sinners, is most assuredly worthy of praise.  For what is more beautiful than fire flaming, blazing, and shining?  What more useful than fire for warming, restoring, cooking, though nothing is more destructive than fire burning and consuming?  The same thing, then, when applied in one way, is destructive, but when applied suitably, is most beneficial.  For who can find words to tell its uses throughout the whole world?  We must not listen, then, to those who praise the light of fire but find fault with its heat, judging it not by its nature, but by their convenience or discomfort.  For they wish to see, but not to be burnt.  But they forget that this very light which is so pleasant to them, disagrees with and hurts weak eyes; and in that heat which is disagreeable to them, some animals find the most suitable conditions of a healthy life.