Catholic Social Teaching is a relatively new and growing body of theology. Its foundation can be found in the Bible and Tradition of the Church. However, it began to be formalized beginning in 1891 with the writing of Pope Leo's revolutionary Social Letter/Encyclical, On the New Things/Rerum Novarum. It subsequently has been woven through all the many Social Encyclicals written by the modern popes, right up to the current pope, Francis.

This book is written about the many themes of Catholic Social Teaching found in these Social Letters as well as an emphasis particularly on distributive justice as found in every modern Papal Social Letter. Additionally, these Letters often discuss the current failures of modern economic systems (Capitalism, Communism, and Socialism) to meet the needs of a majority of people in the world, particularly the poor and marginalized. Although these Social Letters never propose any new economic system, the heavy emphasis on distributive justice found in all of them is used as a basis to discuss a proposed and untried economic system called "Distributism." Distributism was first introduced to the world in the early 1900's by Catholic writer and theologian, G.K. Chesterton and Hilaire Belloc.