8 In this way We daily see the numerous ills which afflict all classes of men. These poisonous doctrines have utterly corrupted both public and private life; rationalism, materialism, atheism, have begotten socialism, communism, nihilism evil principles which it was not only fitting should have sprung from such parentage but were its necessary offspring. In truth, if the Catholic religion is wilfully rejected, whose divine origin is made clear by such unmistakable signs, what reason is there why every form of religion should not be rejected, not upheld, by such criteria of truth? If the soul is one with the body, and if therefore no hope of a happy eternity remains when the body dies, what reason is there for men to undertake toil and suffering here in subjecting the appetites to right reason? The highest good of man will then lie in enjoying life's pleasures and life's luxuries. And since there is no one who is drawn to virtue by the impulse of his own nature, every man will naturally lay hands on all he can that he may live happily on the spoils of others. Nor is there any power mighty enough to bridle the passions, for it follows that the power of law is broken, and that all authority is loosened, if the belief in an ever-living God, Who commands what is right and forbids what is wrong is rejected. Hence the bonds of civil society will be utterly shattered when every man is driven by an unappeasable covetousness to a perpetual struggle, some striving to keep their possessions, others to obtain what they desire. This is well-nigh the bent of our age.
Source: Exeunte Iam Anno (Vatican.va)