The period between the French Revolution and the mid-twentieth century was a period of significant upheaval for Catholicism and in its interpretation of its role in relationship to the growth of nationalism, human rights and international relations. Chapter 1 examines how the Church developed Catholic social and political thought through human rights ideas. Catholicism gradually responded to the emergence of rights-based language, which it initially rejected, and only later engaged in active participation. Section 1.2 appraises in what manner the Catholic Church had available a long cosmopolitan tradition of reflection on the natural law, and this tradition in particular became a resource to a changing political landscape. Section 1.3 appraises the Catholics resolution of the tensions in rights language through the development of the philosophy of Personalism, and a reassessment of democracy as a foundation of cosmopolitan political life. This chapter concludes in Section 1.4 by presenting where those ideas were reaffirmed in later papal declarations and encyclicals.

Modern Catholic Social Teaching (CST) developed in an historical context that posed dramatic challenges to the institutional Church and lay faithful. The French Revolution (1789–1799), the Napoleonic era (1799–1815), and industrial revolution, and waves of succeeding uprisings in 1820, 1830, 1848, and 1870 represented radical challenges to existing political structures, such that Old Regime conceptions of the State and Church alliance of Throne and Altar were no longer tenable. The emergence of the modern secular state in traditionally Catholic lands often included the suppression of religious orders, charitable and educational institutions, and control over clergy and hierarchy. The Church struggled in this revolutionary age of ideology – torn between laissez-faire liberalism and revolutionary socialism. The Catholic movement, primarily of laity, grew in response to these challenges, under the rubrics of the “Religious Question” of freedom of religion, and Church–State relations generally, and of the “Social Question” or how to address the growing number of rootless and impoverished industrial workers in an increasingly secularized political and cultural environment. The revival of neoscholastic philosophy of society became the paradigm through which Pius IX and especially Leo XIII were able to engage modernity on evangelical and natural law foundations.

Although the roots of subsidiarity predate Christianity, we can usefully explore encyclical teaching to appreciate how the Catholic Church has given intelligible expression to this concept in the midst of her broader social teaching. The paradox of subsidiarity is that it mandates contradictory things: requiring on the one hand that the state should not interfere with the internal life of civic associations and on the other hand that the state should provide assistance to those associations when such assistance is necessary. Rather than using the language of "positive" and "negative" subsidiarity (which, it is argued, is not especially helpful because it perpetuates the sovereigntist tendency to see the state as the locus of all authority), this chapter focuses on how the encyclicals illuminate (1) the nature of subsidiarity, as neither freestanding nor abstract; (2) subsidiarity’s political purposes (increased participation in decision making by actors who are more proximate to need and therefore better placed to reach good outcomes more efficiently), moral purposes (protection of associational freedom and avoidance of totalitarianism), and final purposes (protection of that charity which can never be mediated through bureaucracies); and (3) the operationalisation of subsidiarity, which can be promoted or inhibited through the action of law.

Aquinas did not speak of “social” teaching, but did synthesize the teaching of the prophets, the Lord, the Fathers, and sound philosophy concerning social matters and responsibilities. He would have regarded the principles of CST as part of the Church’s doctrine of faith and morality (de fide et moribus), insofar as morality – the living out of that faith which consists in true beliefs about the Creator – embodies the principles, precepts, and virtue(s) of justice. For among the cardinal virtues, justice is the one bearing on those of our choices that relate to or impact on other persons, especially persons with whom in one way or another we are associated. And Aquinas’s treatment of justice, mainly but not only in his Summa Theologiae, is very extensive and detailed. This chapter offers (1) an overview of his significance for CST, (2) a review of the appeals to his writings in Rerum novarum and some of its antecedents and successors, and (3) his contribution to some leading features of CST since then, including dignity and equality; private property and associations; “subsidiarity” and the service conception of authority and law; and “solidarity” (local and global).

This chapter offers a broad overview of the development of Catholic social thought on socialism and capitalism, together with novel interpretations of this tradition. Through a close engagement with magisterial documents, this chapter first provides an account of socialism as the founding heresy of the formal tradition of the social doctrine of the Church, aiming to distill the essence of the Church’s condemnation. It goes on to argue that capitalism is not a similar (but opposite) heresy since capitalism is not in essence an error about human nature and man's relation to created goods. The principles of right order are discussed in relation to capitalism, with the question of just wages receiving a prominent treatment. Finally, drawing on the "twin rocks" passage in Quadragesimo anno, the chapter provides a schema for thinking about the axis of philosophical mistakes related to socialism and capitalism. A brief treatment of private property in the final section is used to illustrate the common but faulty assimilation of individualism and collectivism to capitalism and socialism respectively. For the sake of tractability, this chapter focuses primarily on the development of the social magisterium in the Leonine era.

The common good (bonum commune) has, since antiquity, referred to the aim of social and political association, and was particularly prominent in medieval Christian political theology. Since St. John XXIII’s 1961 encyclical letter, Mater et magistra, ecclesiastical statements about social teaching have employed a formulation of the common good, usually in the version that appeared in the Second Vatican Council’s 1965 Pastoral Constitution for the Church in the Modern World, Gaudium et spes, as “the sum of those conditions of social life that allow social groups and their individual members relatively thorough and ready access to their own fulfillment.” This chapter discusses the origins and development of this formulation as well as the ways that it has been used in subsequent Catholic Social Teaching. While it has sometimes been interpreted as an “instrumental” account of the common good, the sources and uses of the notion suggest that it is the particularly modern political component of a fuller notion of the common good continuous with the tradition. In particular, the recent formulation is concerned to limit the power of the modern state and protect the dignity of the human person in the challenging conditions of political modernity.

Mary Ann Glendon is a prolific and broad-ranging scholar who has also made important forays into public service on behalf of the United States and the Holy See. Her scholarly work can be best understood not as the systematic development or application of a particular jurisprudential school of thought, but rather as the painstaking work of pursuing a series of insights into the transitions to be made in law and in society, across a broad range of discrete topics, around the turn of the twenty-first century. Certain persistent and coherent themes have animated and united her work, especially ideas that resonate deeply with Catholic social thought. Across her scholarly writing on labor and property law, family law, the legal profession, constitutional law, and international human rights, she has remained persistently concerned with the role and importance of mediating institutions of civil society, especially families, with the systemic relationships between law and society, and with the unique importance of comparative methods to help arrive at a sound balance between universal ideals of justice, liberty, and dignity, on the one hand, and the value of the diversity and particularity of local communities, on the other.