This chapter discusses the effect of Pope Francis's own ideology on the Vatican's opposition to ideology of gender. It traces developments over the course of the last half century that first brought the Vatican to embrace complementarity as the foundation of its theological anthropology. To mobilize that anthropology in an attempt to influence secular law in settings as diverse as the United Nations and the French Manif Pour Tous, the protest movement that first brought hundreds of thousands of French citizens onto the streets of Paris to demonstrate against the inclusion of same-sex couples in a law extending "Marriage Pour Tous" in the spring of 2013. Ratzinger condemned as "the obscuring of the difference or duality of the sexes" in the Letter to the Bishops of the Catholic Church on the Collaboration of Man and Woman in the Church and in the World.