11 We have designedly made mention here of virtue and religion. For, it is the opinion of some, and the error is already very common, that the social question is merely an economic one, whereas in point of fact it is, above all, a moral and religious matter, and for that reason must be settled by the principles of morality and according to the dictates of religion. For, even though wages are doubled and the hours of labor are shortened and food is cheapened, yet, if the working man hearkens to the doctrines that are taught on this subject, as he is prone to do, and is prompted by the examples set before him to throw off respect for God and to enter upon a life of immorality, his labors and his gain will avail him naught.
Source: Graves de Communi Re (Vatican.va)