Community of goods is ascribed to the natural law, not that the natural law dictates that all things should be possessed in common and that nothing should be possessed as one’s own: but because the division of possessions is not according to the natural law, but rather arose from human agreement which belongs to positive law [the ius gentium], as stated above (II-II:57:3). Hence the ownership of possessions is not contrary to the natural law, but an addition thereto devised by human reason.
Summa Theologiae II-II. Q66. A2. Ad. 1. “Theft and Robbery”
Private property is one form of ownership. There are also other forms of ownership, such as common property and state property. Private property can be owned individually or cooperatively.
Economists distinguish capital goods (farmland, factories, etc), which can be used for production, from consumer goods, which are used to satisfy our needs (food, clothing, etc). Marxists falsely think that the former kind—productive private property—must be abolished entirely to end capitalism.
The Church teaches that private property is lawful, but that “however the earth may be apportioned among private owners, it does not cease to serve the common interests of all” (Rerum Novarum § 8) and that “not every distribution among human beings of property and wealth is of a character to attain either completely or to a satisfactory degree of perfection the end which God intends. Therefore, the riches that economic-social developments constantly increase ought to be so distributed among individual persons and classes that the common advantage of all will be safeguarded” (Quadragesimo Anno § 57). In other words, supporting private property does not mean supporting capitalism.
In premodern society, private property always existed alongside other forms of ownership and was understood in the context of the common good. Capitalism changed this. In liberalism, a new form of private property came into law which began to see private property as absolute. In the words of John Locke, a foundational thinker of early liberalism, in 1689:
Whatsoever then he removes out of the state that nature hath provided, and left it in, he hath mixed his labour with, and joined to it something that is his own, and thereby makes it his property. It being by him removed from the common state nature hath placed it in, it hath by this labour something annexed to it, that excludes the common right of other men: for this labour being the unquestionable property of the labourer, no man but he can have a right to what that is once joined to, at least where there is enough, and as good, left in common for others. (Two Treatises of Government, Essay Two, Chapter V: “Of Property”)
Locke lays out the foundation in classical liberal law to reject the social nature of private property. This is a sharp departure from “Christian tradition” which “has never recognized the right to private property as absolute and untouchable” (Compendium of the Social Doctrine of the Church § 177). In the words of the Catechism, “the right to private property, acquired or received in a just way, does not do away with the original gift of the earth to the whole of mankind. The universal destination of goods remains primordial…” (CCC § 2403). Finally, Saint Pope John Paul II taught that “the right to private property is subordinated to the right to common use, to the fact that goods are meant for everyone” (Laborem Exercens § 14).
The right to private property can only be considered a secondary natural right, derived from the principle of the universal destination of created goods. This has concrete consequences that ought to be reflected in the workings of society. Yet it often happens that secondary rights displace primary and overriding rights, in practice making them irrelevant.
Pope Francis, Fratelli Tutti § 120