The Question of Contraception.

By the early 1960s new contraceptive methods, particularly the birth-control pill, and growing concern about an exploding world population led some participants at the Second Vatican Council to raise the question of the church's traditional opposition to artificial birth control. The topic seemed ready for debate in the now-open climate of the church. But responding to conservatives in the Vatican, Pope John XXIII instead created a separate papal commission to review the issue. Pope John XXIII was succeeded by Paul VI in 1963, who was more responsive to conservative opposition to changes in traditional church teachings on sexual matters. In 1967 reformers were heartened when a draft report from the commission was leaked, saying that limiting the size of the family was the responsibility of the couple involved.

Humanae Vitae.

But when Pope Paul VI released his encyclical Humanae Vitae in...