With an even clearer awareness, since the Second Vatican Council, of the demands imposed by Christ's Gospel in this area, the Church judges it her duty to help all men explore this serious problem in all its dimensions, and to impress upon them the need for concerted action at this critical juncture.
2. Our recent predecessors did not fail to do their duty in this area. Their noteworthy messages shed the light of the Gospel on contemporary social questions. There was Leo XIII's encyclical Rerum Novarum, (1) Pius XI's encyclical Quadragesimo Anno, (2) Pius XII's radio message to the world, (3) and John XXIII's two encyclicals, Mater et Magistra (4) and Pacem in Terris. (5)