The modern papacy emerged from the clash with the values of Enlightenment and the pope’s loss of temporal power. In a way, popes established themselves as a renovated source of moral authority on bioethics. This chapter aims to trace the history of papal pronouncements on contraception and abortion. It examines the historical roots of Christian sexual ethics from antiquity. It focuses on the early modern origin of the questions concerning the beginning of life and on the modern idea of immediate ensoulment. It shows how modern medical knowledge and eugenics contributed to a new view of reproduction as separate from sexuality, which called into question the traditional sense of marriage and gender roles. In this context, in which anti-modernism certainly played a role, popes condemned birth control, abortion, and women’s emancipation, revealing a huge hiatus between the experience of laity and the inflexible authority of the Catholic Church.

The papacy played a central role in the development of Roman Catholic teaching about bioethics. Pope Pius XI’s Casti connubii (1930) condemned contraception, sterilization, and abortion. Papal teaching was broadly accepted by Catholics before the 1960s. Widespread dissent in the Church greatly increased after the publication of Pope Paul VI’s Humanae vitae (1968). The first successful IVF procedure in 1978 raised new bioethical issues relating to the status of human embryos outside the womb.

The Catholic hierarchy was more successful in lobbying politicians to enact restrictive laws, or obstruct liberal reforms, than in persuading the laity to accept its teaching on birth control and assisted human reproduction. A rift emerged between mainstream Catholic culture and the institutional Church. The Church is now circumscribed in meeting the challenges presented by complex ethical issues, such as surrogacy and assisted dying, because of the papacy’s inflexible stance on these matters.