Truly, it is hardly possible to describe how great are the evils that flow from divorce. Matrimonial contracts are by it made variable; mutual kindness is weakened; deplorable inducements to unfaithfulness are supplied; harm is done to the education and training of children; occasion is afforded for the breaking up of homes; the seeds of dissension are sown among families; the dignity of womanhood is lessened and brought low, and women run the risk of being deserted after having ministered to the pleasures of men. Since, then, nothing has such power to lay waste families and destroy the mainstay of kingdoms as the corruption of morals, it is easily seen that divorces are in the highest degree hostile to the prosperity of families and States, springing as they do from the depraved morals of the people, and, as experience shows us, opening out a way to every kind of evil-doing in public and in private life.
Further still, if the matter be duly pondered, we shall clearly see these evils to be the more especially dangerous, because, divorce once being tolerated, there will be no restraint powerful enough to keep it within the bounds marked out or presurmised. Great indeed is the force of example, and even greater still the might of passion. With such incitements it must needs follow that the eagerness for divorce, daily spreading by devious ways, will seize upon the minds of many like a virulent contagious disease, or like a flood of water bursting through every barrier.
– Leo XIII, Arcanum (1880)