The modern economy is creating a number of problems: human conditions of production, fairness in the exchange of goods and in the division of wealth, the significance of the increased needs of consumption, and the sharing of responsibility (a. 7). Paul points out that, while Leo XIII addressed one specific social problem, the need today is to address a variety of problems (a. 5). The pope calls attention to these problems:
--urbanization: the weakening of agrarian civilization and the inordinate growth of huge concentrations of population (a. 8-9);
--Christians in the city: urbanization upsets the family, the neighborhood, and the very framework of the Christian community (a. 10-12);
--youth: there is a questioning of modes of authority, education for freedom, and the handing on of values and beliefs (a. 13);
--the role of women: many countries are considering charters ending discrimination and establishing relationships of equality in rights (a. 13);
--workers: democratic societies accept the principle of labor union rights but are not always open to their exercise (a. 14);
--victims of changes: new situations of injustice have arisen involving the handicapped and the maladjusted, the old, and different groups of those on the fringe of society (a. 15);
--discrimination: many are discriminated against, in law or in fact, on account of their race, origin, color, culture, sex, or religion (a. 16);
--right to emigrate: a great number emigrant workers and refugees function in precarious situations (a. 17);
--creating employment: population growth raises fears of lack of sufficient employment for everyone (a. 18-19);
--media of social communication: news providers offer a positive service but they also represent as it were a new power involving advantages and risks (a. 20);
--the environment: by an ill-considered exploitation of nature we risk destroying it and becoming victims ourselves (a. 21);
--flagrant inequalities exist in the economic, cultural, and political development of nations (a. 2);
--human rights are too often disregarded, if not scoffed at, or else they receive only formal recognition (a. 23);
--the ambition of many nations, competing among each other, is to attain technological, economic, and military power (a. 45);
--new economic powers are emerging, the multinational enterprises, which can conduct autonomous strategies and can lead to a new and abusive form of economic domination (a. 44).

The keynote of Pope Paul's apostolic letter seems to be complexity and variety. He points out that the complexity of the problems raised is great, in the present intertwining of mutual dependencies (a. 43), and he recognizes that Christians must operate within a diversity of situations, functions, and organizations (a. 49). In line with this acceptance of complexity, Paul acknowledges that socialism takes on different forms according to different continents and cultures, and distinctions must be made to guide concrete choices between the various levels of expression of socialism (a. 31). He even recognizes that some people lay down distinctions between Marxism's various levels of expression (a. 32-34).

Paul accepts that fact that there is a wide diversity among the situations in which Christians find themselves according to regions, socio-political systems, and cultures (a. 3). In view of this diversity, he asserts that in concrete situations, one must recognize a legitimate variety of possible options, so that the same Christian faith can lead to different commitments (a. 50). Christians are to discern the options and commitments necessary to make social, political, and economic changes (a. 4).

Paul's response to complexity is to admit that in the face of such widely varying situations it is difficult for him to utter a unified message and put forward a universally valid solution. He says that he has no ambition or mission to do this, and he calls on local Christian communities to analyze their own situations and apply to them the principles of the social teaching of the Church (a. 4).

He is willing, however, to lay down certain principles and guidelines.
--each country must be allowed to promote its own development, free from any political or economic domination (a. 43);
--all people share the same basic rights and duties, so that within each country all citizens should be equal before the law, find equal admittance to economic, cultural, civic and social life, and benefit from a fair sharing of the nation's riches (a. 16);
--governments and political parties should not try to impose an ideology by means that would lead to a dictatorship over minds (a. 25);
--legislation is necessary, but it is not sufficient for setting up true relationships of justice and equality (a. 23);
--bureaucratic socialism, technocratic capitalism, and authoritarian democracy all being with them materialism, egoism, and constraint (a. 37);
--Marxist ideology is unacceptable because of its atheistic materialism, its dialectic of violence, its absorption of individual freedom in the collectivity, and its denial of all transcendence to human beings (a. 26);
--capitalism also calls for careful discernment because it its very root is an erroneous affirmation of the autonomy of the individual in one's activity, motivation, and exercise of liberty (a. 35);
--utopian criticism of existing society, while risky, can serve the useful purpose of directing the forward-looking imagination towards a fresh future (a. 37);
--the more fortunate should renounce some of their rights so as to place their goods more generously at the service of others (a. 23);
--everyone has the right to work, to develop oneself professionally, to an equitable income, and to assistance in case of need arising from sickness or age (a. 14);
--laws should aim at protecting women's proper vocation and at the same time recognizing her independence as a person and her equal rights to participate in society (a. 13).

Having analyzed the contemporary situation and called attention to the principles that should guide Christians in dealing with this situation Pope Paul issues a call to action. Already in his opening lines the pope had expressed his conviction that Rerum Novarum continues to inspire action for social justice (a. 1), and later he asserts that Christians must involve themselves in the building up of a peaceful and just world (a. 37). The Christian faith demands a just transformation of society (a. 51), and Paul sees the power of the Holy Spirit working within the action of Christians in the service of others (a. 51). He therefore addresses to all Christians a fresh and insistent call to action: their recalling of principles, statements of intentions, pointing out injustices, and uttering prophetic denunciations must be accompanied by an awareness of personal responsibility and by effective action (a. 48). Everyone must determine, in their consciences, the actions which they are called to share in (a. 49).

What kind of action does Pope Paul call for? He points out that economic activity is necessary, but it runs the risk of taking up too much strength and freedom. Thus the need is felt to pass from economics to politics (a. 46), so that the action which the pope is calling for is political action. The passing to the political dimension expresses a demand made by people today: a greater sharing in responsibility and in decision-making (a. 47).