See this online text:

See also the texts listed on the page “Marriage and the Family“ and on the 25 July 2019 post “Online text: “Every Marital Act Ought to be Open to New Life: Toward a Clearer Understanding”, by Germain Grisez et al.

On the Feast of the Annunciation in the one true and Catholic Church. For other texts and ebooks, you may access the List of Free eBooks (Arranged by Title), the List of Free eBooks (Grouped by Subject), the List of Worth-It Catholic Books & eBooks, and the main page of the Catholic eBooks Project.

“In marriage, as the marriage law declares, the man and woman come together for the procreation of children. Therefore whoever makes the procreation of children a greater sin than copulation, forbids marriage, and makes the woman not a wife, but a mistress, who for some gifts presented to her is joined to the man to gratify his passion. Where there is a wife there must be marriage. But there is no marriage where motherhood is not in view; therefore neither is there a wife.”

(Saint Augustine, On the Morals of the Manichaeans, xviii, 65)

“For God, the Lord of life, has conferred on men the surpassing ministry of safeguarding life in a manner which is worthy of man…. The sexual characteristics of man and the human faculty of reproduction wonderfully exceed the dispositions of lower forms of life. Hence the acts themselves which are proper to conjugal love and which are exercised in accord with genuine human dignity must be honored with great reverence.

“Hence when there is question of harmonizing conjugal love with the responsible transmission of life, the moral aspects of any procedure does not depend solely on sincere intentions or on an evaluation of motives, but must be determined by objective standards. These, based on the nature of the human person and his acts, preserve the full sense of mutual self-giving and human procreation in the context of true love. Such a goal cannot be achieved unless the virtue of conjugal chastity is sincerely practiced. Relying on these principles, sons of the Church may not undertake methods of birth control which are found blameworthy by the teaching authority of the Church in its unfolding of the divine law.

“All should be persuaded that human life and the task of transmitting it are not realities bound up with this world alone. Hence they cannot be measured or perceived only in terms of it, but always have a bearing on the eternal destiny of men.”

(Second Vatican Council, Pastoral Constitution “Gaudium et Spes”, 51)

“[I]t is never lawful, even for the gravest reasons, to do evil that good may come of it (cf. Rom 3:8) — in other words, to intend directly something which of its very nature contradicts the moral order, and which must therefore be judged unworthy of man, even though the intention is to protect or promote the welfare of an individual, of a family or of society in general”

(Pope Paul VI, Humanae Vitae, No. 14, as quoted by Pope St. John Paul II, Veritatis Splendor, No. 80)