The thesis examines the Catholic social teaching, as it is expressed in papal encyclicals, in wide context of contemporary political doctrines and major events of 20th century. The author proposes a method of following political messages of the Catholic Church during the last century. He challenges a standard Church's claim of immutability of its teaching. He shows, on the contrary, firm contextualisation both of Church's action and of its official message. From classical confrontational strategy face to modernity, through the attitude of "dialogue" during the Second Vatican Council, the Church insists on remaining a recognized participant of significant contemporary debates even in conditions of postmodernity.