Pope John XXIII
Mater et Magistra §108
Mater et Magistra: On Christianity and Social Progress
108 What, then, of that social and economic principle so vigorously asserted and defended by Our predecessors: man's natural right to own private property, including productive goods? Is this no longer operative today, or has it lost some of its validity in view of the economic conditions We have described above? This is the doubt that has arisen in many minds.
Source: Mater et Magistra (Vatican.va)