Pope John XXIII
Mater et Magistra §111
Mater et Magistra: On Christianity and Social Progress
111 Accordingly, We make Our own the directive of Our Predecessor Pius XII: "In defending the principle of private ownership the Church is striving after an important ethico-social end. She does not intend merely to uphold the present condition of things as if it were an expression of the divine Will, or to protect on principle the rich and plutocrats against the poor and indigent. . . The Church aims rather at securing that the institution of private property be such as it should be according to the plan of the divine Wisdom and the dispositions of Nature." (32) Hence private ownership must be considered as a guarantee of the essential freedom of the individual, and at the same time an indispensable element in a true social order.
Source: Mater et Magistra (Vatican.va)