Pope Pius XII has been identified as the final pope of the “Modern” or “Leonine” school of social thought, stemming from the time of Pope Leo XIII. Key components of thjis school include support for political democracy, support of workers’ rights, support for moderate social welfare policies, and encouragement of lay movements like Catholic Action. These strategies were combined with a philosophical and theological emphasis on Natural Law, a communitarian vision of the human person, and a hierarchical understanding of church and society. Pope Pius XII brought these teachings to the laity in an effort to promote human welfare. Through the principle of subsidiarity, he offered resistance to totalitarian governments, and most importantly, he defended the family as society’s foundational cell, the “natural nursery and school where the man of tomorrow grows up and is formed.” He continued the Vatican practice of forming alliances with democratic nations, but under Pius the Church formed a much closer alliance with the United States. In so doing this, he largely repudiated the so-called “phantom heresy” of Americanism.