An encyclical published by Pope Paul VI in a year of all-around-the-world rebellion : 1968. It is the Church's policy document on all areas concerning human life and sexuality, such as abortion or contraception.
Pope Pius XII took position on the issues of birth control and sexuality as early as 1951 in his Address to the Midwives, but during the Vatican II council Pope Paul VI requested that no developed teaching on sexuality be presented until he heard from a commission on birth control.
The Pontifical Commission on Population and Family Life was established by John XXIII in 1963. The Commission consisted of theologians, priests, bishops, cardinals and laypeople from a variety of professions. They prayed together, listened to presentations from experts, reviewed surveys taken from over 3,000 dedicated Catholic couples from 18 countries, and considered numerous matters pertaining to human sexuality with special emphasis on the birth control question.
On June 28, 1966 the Commission submitted its final report. The vote was 30-5 in stating that the Church's teaching on artificial contraception was in a state of doubt. In its report, the Commission recommended that the procreative aspect of sex should not be tied to every sexual act, but belong to marriage as a whole. They also recommended that couples be free to choose the non-abortive method of family planning that would work best for them.
However, two members of the commission produced a minority report stating that the church should not and could not change its earlier teaching. In response, the Council majority leaked their report to the press in 1967 in hopes of pressuring Paul VI. However, he still promulgated Humanae Vitae (Latin for "of human life") on July 25, 1968, and the document has been the Church's policy document on all issues of human sexuality since then.
The encyclical addressed all issues of Catholic parenthood and sexuality.
It opens with observations on modern life and sexuality, and the fact that couples may wish to limit the number of children. However, the Church's doctrine of marriage is reaffirmed. Marriage is an institution of union where "husband and wife, through that mutual gift of themselves, which is specific and exclusive to them alone, develop that union of two persons in which they perfect one another" and of creation : "Marriage and conjugal love are by their nature ordained toward the procreation and education of children. Children are really the supreme gift of marriage and contribute in the highest degree to their parents' welfare."(1)
As a result, artificial birth control is a strict no-no. There are several arguments against this : it's unnatural, detracts from the purpose of sex as a procreative act, the idea that by messing with fertility man is playing the sorcerer's apprentice and of course the moral decay that would ensue from the possibility of sex without consequence.
Natural family planning methods (abstaining from intercourse during certain parts of the women's cycle) are allowed, since they take advantage of "a faculty provided by nature." Similarly, sterilization, even if temporary, is verboten, but therapeutic means which induce infertility as a side effect are totally fine as long as they are not used for that side effect.
As always, abortion is strictly forbidden as contrary to the Church's doctrine on the nature of human life.
The encyclical closes with several appeals :
- To public authorities to oppose laws which undermine the natural moral law : "We beg of you, never allow the morals of your peoples to be undermined. The family is the primary unit in the state; do not tolerate any legislation which would introduce into the family those practices which are opposed to the natural law of God."
- To scientists : "medical science should by the study of natural rhythms succeed in determining a sufficiently secure basis for the chaste limitation of offspring. In this way scientists, especially those who are Catholics, will by their research establish the truth of the Church's claim that 'there can be no contradiction between two divine laws-that which governs the transmitting of life and that which governs the fostering of married love.'(2)"
- And finally to followers, doctors, nurses and the clergy to uphold and promote the method.
The encyclical has been under constant criticism both from outside and inside the Church.
The most notable form of opposition from inside the Church was a letter signed by most Canadian bishops called The Winnipeg Statement, published in September of 1968 in which, despite affirming solidarity to the Pope and accordance with Humanae Vitae, argued that there are circumstances in which Catholics could be safely assured, in the matter of contraception, that whoever chooses that course which seems right to him does so in good conscience. In other words : ideally you shouldn't do it but if you have to it's no big deal (the basic stance of most of the clergy and an overwhelming majority of Catholics).
John Paul II has always agreed with Paul VI's ideas on these issues(3) and has consistently made explicit his approval of the views expressed in Humanae Vitae. In his 1981 encyclical Familiaris Consortio he describes sex as a "language of love" while condemning artificial contraception, and does it again in 1993 with Veritatis Splendor ("The Splendor of Truth") and in 1995 with Evangelium Vitae.
The Catechism of the Catholic Church, which is the modern compendium of Catholic teaching, upholds the ban on artificial contraception while affirming the unitive and procreative aspects of marriage and sexuality to be equally important.
The issue of contraception is one on which John Paul II won't budge. Any debate on it will have to wait for a new Pope. And even then. Even though there is overwhelming support inside the Church for lifting the ban on contraceptives, such a major policy change doesn't come easy in the Vatican. After all, the Roman Catholic Church is the oldest, largest institution in all of human history -- and that comes with quite a bit of inertia.
The condemnation of abortion has strong ideological and political backing, both inside the clergy and the rest of the Church. I'd give it at least a few centuries -- heck, I'd give it more than our culture.
What's most important about Humanae Vitae however isn't the condemnation of contraception, abortion and premarital hanky-panky. What matters most is that it expresses the Catholic Church's doctrine on life, love and human sexuality. Marriage is a union of life and love : between a complementary man and woman who better each other, and towards the creation of new life. It's a very idealistic view, as everything religious, but also kind of beautiful...
(1) and (2) Second Vatican Council, Pastoral Constitution on the Church in the World of Today.
(3) Some sources claim that then-Cardinal Karol Wojtyla was part of the Pontifical Commission and even participated in the writing of the minority report, but I see no trace of it in his quite-detailed official Biography. I'll trust the Church on this one because they have no reason to lie and media outlets often make small sloppy mistakes like this, but I thought I'd mention this for the sake of exhaustivity.