on issues relating to sexual morality and marriage, one example being Giovanni Maria Chiericato (Joannes Clericati) in his Decisiones de Matrimonio. The Church Doctor St. Alphonsus Liguori, a preeminent moral theologian, considered therapeutic abortions to save the mother from immediate danger justified. Pope Pius IX in his 1869 bull, Apostolicae Sedis, instituted a Church policy labeling all abortion as homicide and condemning abortion regardless of the stage of pregnancy since Pope Sixtus V in his 1588 bull. However, some readings of Apostolicae Sedis meant that the excommunication for abortion didn't extend to the mother. Magisterium since 1917 1917 Code of Canon Law extended excommunication for abortion to the mother Casti connubii (1930) by Pope Pius XI Casti connubii was written in part as a response to the decision of the Anglican Lambeth Conference in 1930 that taught the legitimacy of the use of contraception in some circumstances. "Any use whatsoever of matrimony exercised in such a way that the act is deliberately frustrated in its natural power to generate life is an offense against the law of God and of nature, and those who indulge in such are branded with the guilt of a grave sin." Humanae vitae (1968) by Pope Paul VI Persona humana (1975) by the Congregation for the Doctrine of the Faith Theology of the Body by Pope John Paul II Evangelium vitae (1995) by Pope John Paul II Donum Vitae (1987) by the Congregation for the Doctrine of the Faith Veritatis splendor (1993) by Pope John Paul II Catechism of the Catholic Church (1992) Deus caritas est (2005) by Pope Benedict XV Amoris laetitia (2016) by Pope Francis Dissent A study published in 1977, titled Human Sexuality: New Directions in American Catholic Thought, after being commissioned in 1972 by the Catholic Theological Society of America (CTSA), which however did not approve the study, showed that dissent from the Holy See's teachings on sexuality was common among United States theologians. Reaction to the study showed that the dissent was not unanimous and brought about controversies inside the CTSA itself. In 1979, the Sacred Congregation for the Doctrine of the Faith publicised an advisory that deplored the books's "erroneous conclusions", identified "numerous misreadings of the teaching of the Second Vatican Council" in it, and said that the book diminished "the morality of sexual love to a matter of 'personal sentiments, feelings, [and] customs ... .'" George Weigel restates