The Catholic Church holds that sex is designed by God to be both unitive and procreative, and that attempting to separate these two aspects of human sexuality through artificial contraception is immoral.
Normally, if a married couple faces a just reason to avoid pregnancy, the Church teaches that they may do so through Natural Family Planning, a process that works with a woman's natural fertile cycles and abstaining from sexual activity during the times that she is fertile.
In their counter-document, the 500 Catholic scholars maintained that Church teaching is "true and defensible" on the basis of Scripture and reason. They described Jesus Christ's sacrifice on the Cross as "the ultimate and complete self-gift" linked to the biblical spousal imagery of Christ and the Church.
They charged that the Wijngaards statement's authors "virtually ignored" the work of St. John Paul II and his Theology of the Body.
"There he demonstrates that our very bodies have a language and a 'spousal meaning' – that they express the truth that we are to be in loving and fruitful relationships with others," the Catholic scholars said in their document.
Human sexual relations fulfill God's intent only when they "respect the procreative meaning of the sexual act" and take place as a "complete gift of self" within marriage, they continued.
The Church asks the faithful to "deepen their relationship" with God, to be open to the direction of the Holy Spirit, and to ask Jesus Christ to "provide the graces needed to live in accord with God's will for their married lives, even the difficult moral truths."
"The widespread use of contraception appears to have contributed greatly to the increase of sex outside of marriage, to an increase of unwed pregnancies, abortion, single parenthood, cohabitation, divorce, poverty, the exploitation of women, declining marriage rates, as well as to declining population growth in many parts of the world," the Catholic document said.
Critics of the Wijngaards statement said they would issue a more detailed response in a forthcoming text called "Self-gift: the heart of Humanae Vitae."
The 1968 revolt against "Humanae Vitae" followed several years of global lobbying and organizing by wealthy foundations involved in population control and other forms of birth control advocacy.
Donald T. Critchlow, in his 1999 Oxford University Press book "Intended Consequences: Birth Control, Abortion, and the Federal Government in Modern America," said that in the 1960s, the wealthy heir John D. Rockefeller III and others within the foundation community were "astutely aware of the importance of changing the Catholic Church's position on birth control."
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They saw a series of meetings at the University of Notre Dame from 1963 to 1967 as an opportunity to ally with Catholic leaders who could "help change opinion within the hierarchy," Critchlow said. These meetings, sponsored by the Rockefeller Foundation and the Ford Foundation, brought together selected Catholic leaders to meet with leaders of the Planned Parenthood Federation of America and the Population Council, as well as with leaders in the two foundations.