For a good understanding of the Church and its view on “social justice” the following documents should be a must read.
Rerum Novarum (On the Condition of Labor) – Pope Leo XIII, 1891
Quadragesimo Anno (After Forty Years) – Pope Pius XI, 1931
Mater et Magistra (Christianity and Social Progress) – Pope John XXIII, 1961
Pacem in Terris (Peace on Earth) – Pope John XXIII, 1963
Gaudium et Spes (Pastoral Constitution on the Church in the Modern World)
Vatican Council II, 1965
Populorum Progressio (On the Development of Peoples) – Pope Paul VI, 1967
Octogesima Adveniens (A Call to Action) – Pope Paul VI, 1971
Justicia in Mundo (Justice in the World) – Synod of Bishops, 1971
Laborem Exercens (On Human Work) – Pope John Paul II, 1981
Solicitudo Rei Socialis (On Social Concern) – Pope John Paul II, 1987
Centesimus Annus (The Hundredth Year) – Pope John Paul II, 1991
Evangelium Vitae (The Gospel of Life) – Pope John Paul II, 1995
Fides et Ratio (Faith and Reason) – Pope John Paul II, 1998
Deus Caritas Est (God Is Love) – Pope Benedict XVI, 2005
Sacramentum Caritatis (Apostolic Exhortation on the Eucharist) – Pope Benedict XVI, 2007
Caritas in Veritate (In Charity and Truth) – Pope Benedict XVI, 2009