9 But Catholic wisdom, sustained by the precepts of natural and divine law, provides with especial care for public and private tranquility in its doctrines and teachings regarding the duty of government and the distribution of the goods which are necessary for life and use. For, while the socialists would destroy the "right" of property, alleging it to be a human invention altogether opposed to the inborn equality of man, and, claiming a community of goods, argue that poverty should not be peaceably endured, and that the property and privileges of the rich may be rightly invaded, the Church, with much greater wisdom and good sense, recognizes the inequality among men, who are born with different powers of body and mind, inequality in actual possession, also, and holds that the right of property and of ownership, which springs from nature itself, must not be touched and stands inviolate. For she knows that stealing and robbery were forbidden in so special a manner by God, the Author and Defender of right, that He would not allow man even to desire what belonged to another, and that thieves and despoilers, no less than adulterers and idolaters, are shut out from the Kingdom of Heaven. But not the less on this account does our holy Mother not neglect the care of the poor or omit to provide for their necessities; but, rather, drawing them to her with a mother's embrace, and knowing that they bear the person of Christ Himself, who regards the smallest gift to the poor as a benefit conferred on Himself, holds them in great honor. She does all she can to help them; she provides homes and hospitals where they may be received, nourished, and cared for all the world over and watches over these. She is constantly pressing on the rich that most grave precept to give what remains to the poor; and she holds over their heads the divine sentence that unless they succor the needy they will be repaid by eternal torments. In fine, she does all she can to relieve and comfort the poor, either by holding up to them the example of Christ, "who being rich became poor for our sake,(18) or by reminding them of his own words, wherein he pronounced the poor blessed and bade them hope for the reward of eternal bliss. But who does not see that this is the best method of arranging the old struggle between the rich and poor? For, as the very evidence of facts and events shows, if this method is rejected or disregarded, one of two things must occur: either the greater portion of the human race will fall back into the vile condition of slavery which so long prevailed among the pagan nations, or human society must continue to be disturbed by constant eruptions, to be disgraced by rapine and strife, as we have had sad witness even in recent times.
Source: Quod Apostolici Muneris (Vatican.va)