Rerum Novarum  (On the Condition of Labor) — Pope Leo XIII, 1891

This seminal work on modern Catholic social thought addresses the plight of the industrial workers in the wake of the Industrial Revolution. It calls for the protection of the weak and the poor through the persuit of justice while excluding socialism and class struggle as legitimate principles of change. It affirms the dignity of work, the right to private property, and the right to form and join professional associations.

Quadragesimo Anno (After Forty Years)—- Pope Pius XI, 1931

Writing in response to the alarming concentration of wealth and power in the socio-economic realm, Pius XI calls for the reestablishment of a social order based on the principle of subsidiarity. In commemorating the 40th anniversary of Rerum Novarum, this encyclical reaffirms the need for a social order animated by justice. 

Mater et Magistra  (Christianity and Social Progress) — Pope John XXIII, 1961

Applying the teachings of his predecessors to modern problems, and affirming the role of the Church as a teacher, and as a nurturing guardian of the poor and oppressed, John XXIII calls for a greater awareness of the need for all peoples to live as one community with a common good. Special attention is focused on the plight of the farmers and farm workers in depressed rural, agricultural economies.

Pacem in Terris (Peace on Earth) — Pope John XXIII, 1963

Covering the entire spectrum of relations between individuals, between the individual and the community, and between nations, John XXIII affirms the inviolability of human rights. Peace, based on mutual trust, can be well-founded only if undergirded by a unity of right order in human affairs arising from a genuine respect for and adherence to the law of God.

Gaudium et Spes (Pastoral Constitution on the Church in the Modern World – Vatican Council II, 1965

Calling for a new sense of service by the Church in a rapidly changing world, the Council presents the ethical framework of the Church’s commitment to pastoral work in the world. This servant Church addresses itself to the real concerns and problems faced by Christians living in the modern age and calls for a development based on an unqualified accceptance of the inherent dignity of the human person.

Populorum Progressio (On the Development of Peoples) — Pope Paul VI, 1967

Calling attention to the worsening marginalization of the poor, Paul VI presents the various dimensions of an integral human development and the necessary conditions for growth in the solidarity of peoples. Only with an accompanying theological reflection on liberation from injustice and genuine human values can there be true development towards a more human condition.

Octogesima Adveniens (A Call to Action )— Pope Paul VI, 1971

Realizing the need for a genuine renewal in domestic and international societal structures, Paul VI calls on Christians to live up to the duty of participation in social and political reform as a way of discovering the truth and living out the Gospel.

Justitia in Mundo (Justice in the World) — Synod of Bishops, 1971

Calling attention to the structural roots of injustice afflicting human relations, the Bishops declare that action in the pursuit of justice, and participation in the transformation of the world are constitutive elements in the Church’s mission of preaching the Gospel.

Laborem Exercens  (On Human Work) — Pope John Paul II, 1981

Exhorting Christians everywhere to be involved in the transformation of existing socio-economic systems, John Paul II presents work as a fundamental dimension of human existence through which the “social question” must be viewed. The meaning of work can only be properly understood when the dignity of labor is taken as an underlying premise.

Solicitudo Rei Socialis  (On Social Concern) — Pope John Paul II, 1987

Expanding on the notion of development in Populorum Progressio, John Paul II reviews the state of world development in the past two decades. The moral nature of development leading humanity to the “fullness of being” is emphasized.  

Centesimus Annus (The Hundredth Year) — Pope John Paul II, 1991

Pope John Paul II addresses a strong critique of the “welfare state” and “real socialism” by arguing that they have a fundamental anthropological error and that a collective and qualitative human needs cannot be satisfied by market mechanisms.  Nation should make an active contribution to the common good of humanity, such as a just wage, social insurance for the elderly and unemployed, protection of workers.  Private property is for universal destination of the earth’s goods and social function, which holds subsidiarity and solidarity together.  Patterns of consumption and structures of power do not enable the poor to gain a sense of human dignity, for there is little respect for human subjective of individuals on the margins of society. 

Evangelium Vitae  (The Gospel of Life) — Pope John Paul II, 1995

Evangelium Vitae is rooted in the Incarnation, who is the source of life and the expression of God’s love to humanity with special favor shown to the poorest and neediest.  Pope John Paul II addressed against ethical relativism, particularly the culture of death and its network of complicity in support of abortion.  He argues further for the need for general mobilization of consciences and cultural transformation through evangelization. 

Deus Caritas Est (God Is Love) — Pope Benedict XVI, 2005

Pope Benedict XVI clarifies some essential facts of the love that God offers human beings and its intrinsic link to the reality of human love.  The ecclesial exercise of the commandment of love calls forth a renewal of commitment in the human response to God’s love. In Agape which human love is transformed into “ecstasy,” and self-giving also becomes self-discovery.  The Church’s charitable activity expresses the essence of Christian and ecclesial charity. Christian charitable activity extends God’s love for His creation, and Christian activity must be based on a personal encounter with Christ, who awakens our love of neighbor. 

Caritas in Veritate  (In Charity and Truth) — Pope Benedict XVI, 2009

In Caritas in Veritate, which relates to Pope Leo XIII’s Rerum Novarum” and Populorum Progressio, Pope Benedict XVI deepens the Church’s social doctrine by focusing on its principles: love in truth and, particularly, the practice of justice for the common good. Justice is inextricably connected with charity, which requires us to be at least just. Thus, we need to develop the fundamental values of justice and love to build a better future based on justice, love, and peace.

Laudato Si (Praised Be to You) –Pope Francis I, 2015

Basing his views on a method of Catholic Social Teaching (See-Judge-Act) Pope Francis I addresses the present ecological crisis by applying principles of the Judeo-Christian tradition in Laudato Si.  This document reveals the root causes of the crisis, such as technology, technocratic mentality, anthropocentrism, practical relativism, employment policies, biological technologies, and human greed. Pope Francis points out how these issues cause disorder and problems for all creature.  Thus, he calls for conversion of both individual and communal acts, urges national and international leaders to care for the safety of creation in making policies, and promotes the role of education in reshaping our individual habits and behaviors.  The whole of creation will be better if everyone takes responsibility in his or her daily life to care for nature and thus work for justice and peace on earth.