The first popes who contributed to modern Catholic social teaching (most notably, Leo XIII and Pius XI) affirmed the right of private property, though they urged owners to exercise social responsibility in sharing surplus property with the needy. As Catholic reflection on the expanding capitalist system of the twentieth century progressed, the Church came to emphasize the “social mortgage” on property wherein property must serve the common good. States had a duty to tax, spend and to otherwise regulate the economy in order to advance social purposes (such as the sustenance of the lives of the poor), and even to appropriate some property to ensure the attainment of these common purposes. Private property rights, however, remained intact, especially to support the human dignity of the poor.
Pope John Paul II in Centesimus Annus affirmed private property rights but insisted that they be modified by the principle of the universal destination of goods, rooted in biblical creation and the Gospel of Jesus. He wrote:
Ownership of the means of production, whether in industry or agriculture, is just and legitimate if it serves useful work. It becomes illegitimate, however, when it is not utilized or when it serves to impede the work of others in an effort to gain a profit which is not the result of the overall expansion of work and the wealth of society, but rather is the result of curbing them or of illicit exploitation, speculation or the breaking of solidarity among working people. Ownership of this kind has no justification and represents an abuse in the sight of God and man.
John Paul explained that “ownership morally justifies itself in the creation … of opportunities for work and human growth for all”.
The pope noted key shifts in the nature of property: from land to capital to know-how, technology, and skill.
Whereas at one time the decisive factor of production was the land and later capital—understood as a total complex of the instruments of production—today the decisive factor is increasingly man himself, that is, his knowledge, especially his scientific knowledge, his capacity for interrelated and compact organization as well as his ability to perceive the needs of others and to satisfy them.
This led to a deeper insight into widespread poverty—excluding people from productive systems:
They have no possibility of acquiring the basic knowledge which would enable them to express their creativity and develop their potential. They have no way of entering the network of knowledge and intercommunication which would enable them to see their qualities appreciated and utilized. Thus, if not actually exploited, they are to a great extent marginalized; economic development takes place over their heads, so to speak, when it does not actually reduce the already narrow scope of their old subsistence economies.
Unable to compete or to meet needs by traditional means, their poverty, powerlessness, and marginalization intensifies. In his words, “In fact, for the poor, to the lack of material goods has been added a lack of knowledge and training which prevents them from escaping their state of humiliating subjection”.
This inability to access productive systems and markets indicates how limited, for John Paul, was the market’s efficiency. It signals yet another area where government and subsidiary institutions must act in solidarity with the poor to ensure the common good. Efforts to meet human needs must be combined with education, technical training, development assistance, technology and internet access, and other efforts to remove barriers and to ensure equality of opportunity and participation.
Property-holding by the widest number of people, then, is critically important. So too is worker participation in the control and ownership of productive enterprises and empowerment and economic development among communities thought to be powerless and under-resourced. Justice also requires, as Pope Benedict pointed out, access to international and other markets by the poor and by underdeveloped nations. Since he took office in 2013, Pope Francis has also consistently called attention to the plight of those excluded from the benefits of holding property, insisting on reforms of the global capitalist system that all too often relegates the poor to the status of “throwaway” people. In the view of all recent Catholic leaders, governments, corporations, and people of means have a moral obligation to use their accumulated property for the benefit of those who control far less of God’s material gifts.
See, for example, discussion in the social encyclical of Pope Benedict XVI. (2009). Caritas in Veritate, 36.
 Pope John Paul II. (1991). Centesimus Annus.
 Ibid., Section 6.
 Ibid., Sections 30-31.
 Ibid., Section 43.
 Ibid., Section 32
 Ibid., Section 33
 Caritas in Veritate, 58.