Pacem In TerrisThe entire encyclical was an affirmation of human rights and duties, appealing to its audience on the grounds of a common humanity within a global community. While it echoes and develops certain ideas put forth in Pope John's 1961 encyclical Mater et Magistra, it is the first Vatican document to address issues essentially on an international order. The only way to establish peace on earth is to follow God's order.