22. Special tasks and responsibilities with regard to the Great Jubilee of the Year 2000 belong to the ministry of the Bishop of Rome. In a certain sense, all the Popes of the past century have prepared for this Jubilee. With his programme to renew all things in Christ, Saint Pius X tried to forestall the tragic developments which arose from the international situation at the beginning of this century. The Church was aware of her duty to act decisively to promote and defend the basic values of peace and justice in the face of contrary tendencies in our time. The Popes of the period before the Council acted with firm commitment, each in his own way: Benedict XV found himself faced with the tragedy of the First World War; Pius XI had to contend with the threats of totalitarian systems or systems which did not respect human freedom in Germany, in Russia, in Italy, in Spain, and even earlier still in Mexico. Pius XII took steps to counter the very grave injustice brought about by a total contempt for human dignity at the time of the Second World War. He also provided enlightened guidelines for the birth of a new world order after the fall of the previous political systems.

Furthermore, in the course of this century the Popes, following in the footsteps of Leo XIII, systematically developed the themes of Catholic social doctrine, expounding the characteristics of a just system in the area of relations between labour and capital. We may recall the Encyclical Quadragesimo Anno of Pius XI, the numerous interventions of Pius XII, the Encyclicals Mater et Magistra and Pacem in Terris of John XXIII, the Encyclical Populorum Progressio and the Apostolic Letter Octogesima Adveniens of Paul VI. I too have frequently dealt with this subject: I specifically devoted the Encyclical Laborem Exercens to the importance of human labour, while in Centesimus Annus I wished to reaffirm the relevance, one hundred years later, of the doctrine presented in Rerum Novarum. In my Encyclical Sollicitudo Rei Socialis I had earlier offered a systematic reformulation of the Church's entire social doctrine against the background of the East-West confrontation and the danger of nuclear war. The two elements of the Church's social doctrine—the safeguarding of human dignity and rights in the sphere of a just relation between labour and capital and the promotion of peace—were closely joined in this text. The Papal Messages of 1 January each year, begun in 1968 in the pontificate of Paul VI, are also meant to serve the cause of peace.