From Graves de communi:
5. What Social Democracy is and what Christian Democracy ought to be, assuredly no one can doubt. The first, with due consideration to the greater or less intemperance of its utterance, is carried to such an excess by many as to maintain that there is really nothing existing above the natural order of things, and that the acquirement and enjoyment of corporal and external goods constitute man’s happiness. It aims at putting all government in the hands of the masses, reducing all ranks to the same level, abolishing all distinction of class, and finally introducing community of goods. Hence, the right to own private property is to be abrogated, and whatever property a man possesses, or whatever means of livelihood he has, is to be common to all.
6. As against this, Christian Democracy, by the fact that it is Christian, is built, and necessarily so, on the basic principles of divine faith, and it must provide better conditions for the masses, with the ulterior object of promoting the perfection of souls made for things eternal. Hence, for Christian Democracy, justice is sacred; it must maintain that the right of acquiring and possessing property cannot be impugned, and it must safeguard the various distinctions and degrees which are indispensable in every well-ordered commonwealth. Finally, it must endeavor to preserve in every human society the form and the character which God ever impresses on it. It is clear, therefore, that there in nothing in common between Social and Christian Democracy. They differ from each other as much as the sect of socialism differs from the profession of Christianity.