Consider the following scenario:
Up until now, the Church has always taught that contraceptive use in the marital act or any direct sex act as in the case of fornication or adultery is always intrinsically evil. However, Bishop Gumbo of the Oopsie diocese in an island of the Pacific Ocean has told his priests that this is no longer the Catholic moral teaching: “The doctrine has evolved.” The reasons are quite evident given the changing circumstances of his diocese.
There has been such a revolution in sexual morality that people now believe that previous generations only considered acts immoral because they were afraid of hell. This idea has now given way to a new “positive” view of the sex act between any two consenting persons of the same or opposite sex. Love is the principle. What makes an action evil, according to this “evolved” way of thinking, is the intention and the circumstances, not the act itself. The Lambeth Conference of the Anglican church got it right back in 1930, which asserted that selfishness is no reason to practice contraceptive love but severe hardships are good reasons. Even St. Thomas Aquinas asserted that a conjugal act done with lusting after another imaginary person(s) is wrong, even though the material act can be physically integral. It has taken centuries to realize that completely abstaining from sexual expression is an extreme and even a heroic act on the part of loving couples in a successful marriage and really isn’t obligatory. It is really in the line of a non-binding counsel rather than a strict law of God. We also see that for the married, too many children in a family causes hardships economically and renders parents relatively incapable of educating their children for life. What the Church calls the evolution of doctrine has now taken place on our little island (Taken from the diocesan newspaper, Catholic Departures).
Any ordinary Catholic with some knowledge of the teaching of the Church can see errors throughout these paragraphs. What the imaginary bishop is calling evolution is, in fact, “rationalization” for sinning. It is a misunderstanding of the two kinds of “evolution.” One is called heterogeneous evolution and the other homogeneous evolution: the first is a corruption and not in continuity of understanding with previous teaching and the other is a logical development of previous teaching. They stand in contradiction to one another.
Teenagers easily rationalize their sins by not calling them sins, instead using other labels like “authenticity” or “true love,” “caring.” More sophisticated adults come up with phrases like, “if you cannot remain chaste, then use a condom.” Other even more knowledgeable thinkers would say, “Humans have their own ideas about human happiness which we must tolerate and accept this diversity of opinion even if we find it repellent.” “What is wrong for you may be right for someone else based on their vision of fulfillment.” These old erroneous principles of human action are not in continuity with reason and faith and do not evolve deeper into the truth that, for example, chastity is always a virtue and actions not chaste are gravely or materially sinful given certain conditions of free consent. Likewise, Sacred Scripture does not allow tolerance for those disobeying divine laws. One does not achieve ultimate beatitude any old way on one’s own but in union with the will of God, which is unchangeable.
On the other hand, homogeneous development of Catholic doctrine of dogma or morals has such a continuity that it does not contradict previous teaching but sees more into it, which is one of the seven notes given Bl. Cardinal Newman on this question. Take for example the teaching on “family planning.” Before the discovery of the science of human reproduction, “family planning” meant engaging in conjugal acts and accepting the children “God sent” or accepting God’s will when he did not send offspring. Then when the female oocyte (egg) was discovered in the process of generation, and that both sperm and egg contained chromosomes of equal number, and that there exists in a woman’s cycle periods of infertility, that breast feeding causes temporary sterility, these and other facets of human generation led to a homogeneous evolution of the meaning of conjugal acts. With proper study of the female cycle, one could chastely engage in marital sexual acts that “the female nature” renders infecund with the correct motives of openness to potential life and actual love of one’s spouse as acts of holy friendship. Then, welcoming human life as a gift would not be sporadic or unplanned by chance but could be integrated into the whole plan of a family’s overall common good. One, therefore, does not manipulate or do violence to the conjugal act against potential conception of a human being by pills, metal or plastic instruments but by accepting the environment the human female’s cycle created by God.
It took decades of difficult pondering on the part of theologians, considering scientific discoveries, to understand how one can authentically plan a family morally. Moreover, in other areas of moral theology, discovering the moral goodness of donating blood and certain specific organs of a living human person; artificial nutrition and hydration for the semi-permanently unconscious person; the removal of cancerous uterus containing a non-viable fetus; and other complex issues took many decades for the Church to work through. Before the resolution by the Magisterium, much hard debate took place among bishops and theologians of different schools of thought. There are still pending issues (more or less) that need further reflection among theologians argued in journals to discover a moral good or evil existing in the adoption of embryos, assisting conjugal intercourse to produce pregnancies (GIFT or TOTS), brain death issues, plan B for rape cases, the use of methotrexate and salpingostomy for tubal pregnancies.
No one can simply argue a position by simply saying there has been an evolution in the teaching of the Church. There is true and false evolution based upon sound or false reasoning from the Tradition found in Sacred Scripture, General Councils of the Church, definitive teaching of the popes together with settled principles used by the theologians such as the principle of totality (also called therapeuticity) in bioethics among others from fundamental moral theology.
True evolution of doctrine after many years of collective reflection on the part of theologians and bishops, in other words, does not ultimately produce a contradiction to previous teaching but is an integration of past teaching by discovering a deeper truth in the sacred deposit of dogma and morals. This also called a legitimate development and renewal of doctrine, not a reversal. Several bishops at the last Synod on the family used this phrase “evolution of doctrine” often without making the proper nuances and distinctions.