Pope John XXIII wrote an encyclical in 1961, and he believed at the time there was a need to continue the tradition of Rerum Novarum (1891) and Quadragesimo Anno (1931). 

In the ’60s, the world had changed considerably when you compare it the 1891 and even 1931, both politically and economically. When 1961 came around the Great Depression, and World War II was being written in history books. Many of us at the time studied it as part of “modern history,” the cold war had begun and was starting to heat up, we had a young president in the White House and technology was beginning to advance at a rate that was mindblowing for the average citizen anywhere in the world. Technology, for the first time, was demonstrating how to achieve increased productivity, but vast poverty remained across the globe.

John XXIII wrote, “Mater Et Magistra,” a document that explores the role the Church(and at this point, I would say any church, religion, etc.) in efforts to achieve social progress and restorative justice in the world. Since the writings on economics by previous Popes, the world had seen tremendous changes such as the discovery of nuclear energy, advanced communications, and political independence movements.

John XIII drives home the point. “There cannot be peace or justice on earth until all of humanity recognizes the dignity of humans as creations of God.”

I think we have forgotten the great encyclicals of John XIII and the entire collection of the Documents of Vatican II. I believe this is a case of “out of sight out of mind.“

“This era in which we live is in the grip of deadly errors; deep disorders tear it. But it is also an era which offers to those who work with the Church immense possibilities in the field of the apostolate. And therein lies our hope.” paragraph 260

I would suggest for ‘bedtime reading” take the encyclical, and as you read it, think of what we have learned since 1961.

http://www.vatican.va/content/john-xxiii/en/encyclicals/documents/hf_j-xxiii_enc_15051961_mater.html