Leo XIII wisely taught "that God has left the limits of private possessions to be fixed by the industry of men and institutions of peoples." That history proves ownership, like other elements of social life, to be not absolutely unchanging, We once declared as follows: "What diverse forms has property had, from that primitive form among rude and savage peoples, which may be observed in some places even in our time, to the form of possession in the patriarchal age; and so further to the various forms under tyranny (We are using the word tyranny in its classical sense); and then through the feudal and monarchial forms down to the various types which are to be found in more recent times."That the State is not permitted to discharge its duty arbitrarily is, however, clear. The natural right itself both of owning goods privately and of passing them on by inheritance ought always to remain intact and inviolate, since this indeed is a right that the State cannot take away: "For man is older than the State," and also "domestic living together is prior both in thought and in fact to uniting into a polity." Wherefore the wise Pontiff declared that it is grossly unjust for a State to exhaust private wealth through the weight of imposts and taxes. "For since the right of possessing goods privately has been conferred not by man's law, but by nature, public authority cannot abolish it, but can only control its exercise and bring it into conformity with the common weal."Yet when the State brings private ownership into harmony with the needs of the common good, it does not commit a hostile act against private owners but rather does them a friendly service; for it thereby effectively prevents the private possession of goods, which the Author of nature in His most wise providence ordained for the support of human life, from causing intolerable evils and thus rushing to its own destruction; it does not destroy private possessions, but safeguards them; and it does not weaken private property rights, but strengthens them.
The State has the further right to intervene when particular monopolies create delays or obstacles to development. In addition to the tasks of harmonizing and guiding development, in exceptional circumstances the State can also exercise a substitute function, when social sectors or business systems are too weak or are just getting under way, and are not equal to the task at hand. Such supplementary interventions, which are justified by urgent reasons touching the common good, must be as brief as possible, so as to avoid removing permanently from society and business systems the functions which are properly theirs, and so as to avoid enlarging excessively the sphere of State intervention to the detriment of both economic and civil freedom.In recent years the range of such intervention has vastly expanded, to the point of creating a new type of State, the so-called "Welfare State". This has happened in some countries in order to respond better to many needs and demands, by remedying forms of poverty and deprivation unworthy of the human person. However, excesses and abuses, especially in recent years, have provoked very harsh criticisms of the Welfare State, dubbed the "Social Assistance State". Malfunctions and defects in the Social Assistance State are the result of an inadequate understanding of the tasks proper to the State. Here again the principle of subsidiarity must be respected: a community of a higher order should not interfere in the internal life of a community of a lower order, depriving the latter of its functions, but rather should support it in case of need and help to coordinate its activity with the activities of the rest of society, always with a view to the common good.By intervening directly and depriving society of its responsibility, the Social Assistance State leads to a loss of human energies and an inordinate increase of public agencies, which are dominated more by bureaucratic ways of thinking than by concern for serving their clients, and which are accompanied by an enormous increase in spending. In fact, it would appear that needs are best understood and satisfied by people who are closest to them and who act as neighbours to those in need. It should be added that certain kinds of demands often call for a response which is not simply material but which is capable of perceiving the deeper human need. One thinks of the condition of refugees, immigrants, the elderly, the sick, and all those in circumstances which call for assistance, such as drug abusers: all these people can be helped effectively only by those who offer them genuine fraternal support, in addition to the necessary care.
John Paul II