"..reason attests that there are objects of the human act which are by their nature “incapable of being ordered” to God, because they radically contradict the good of the person made in his image. These are the acts which, in the Church’s moral tradition, have been termed “intrinsically evil” (intrinsece malum); they are such always and per se, in other words, on account of their very object, and apart from the ulterior intentions of the one acting and the circumstances (Veritatis splendor, no. 80, 1)
A question has been asked in one of my comboxes so I thought it would be best to answer in a separate post. The question is as follows,
Rhythm method is not a sexual act but neither is taking birth control. Both of these thing come from the same intent of heart to be non procreative. They both are not full proof but originate from the same desire. How can the church be ok with the premise of stopping life but only be ok with one method. In everything I have studied I have concluded that it is either 100% wrong to prevent life by any measure or if I admit that the church is smarter than I and that preventing life is ok by them then I have to believe that contraception is ok(absent of abortive ones) as long as you are open to life and share the marital act with your spouse. I have been researching this for almost a year and this is what I have concluded to hear your response would be welcoming and hopefully enlightening.Response,
In order to understand why the Church can allow in some circumstances a couple to refrain from sexual intercourse for the purpose of avoiding conception we must understand the Church's teaching on the conjugal act itself. The first point to be taken is that the sexual act can only be viewed as licit within the confines of marriage between a man and a women. The second point is to understand that there are two purposes, or blessings involving the sacrament of marriage. The first of these considers childbearing, "The first blessing, then, is a family, that is to say, children born of a true and lawful wife. So highly did the Apostle esteem this blessing that he says: The woman shall be saved by bearing children. These words are to be understood not only of bearing children, but also of bringing them up and training them to the practice of piety...". (Catechism of Trent) The second involves fidelity and unity, "The second advantage of marriage is faith, not indeed that virtue which we receive in Baptism; but the fidelity which binds wife to husband and husband to wife in such a way that they mutually deliver to each other power over their bodies, promising at the same time never to violate the holy bond of Matrimony." (Catechism of Trent) Also the bond resembles the relation of marriage to Christ and His Church, "This religious character of marriage, its sublime signification of grace and the union between Christ and the Church, evidently requires that those about to marry should show a holy reverence towards it, and zealously endeavor to make their marriage approach as nearly as possible to the archetype of Christ and the Church." (Casti Connubbi) A proper view of marriage then is important so as not to distort the conjugal act which is being done on a daily basis by those in the media. Father John Hardon makes the point, "Sexual pleasure is not an end in itself. Its divinely ordained purpose is to foster the procreation of children and to sustain the mutual selfless love of husband and wife. If you separate sexual pleasure from this two-fold purpose you are opening the door to what we are calling sexual suicide."
Looking at the conjugal act then in the context of marriage, the natural outcome of this act is conception, or at least the possibility, taking into consideration bodily defects which would prohibit conception. The act of taking artificial contraception involves two things, the intention of the person taking the chemical to avoid pregnancy and the physical deformation caused by the chemical to the body to keep it from functioning according to its natural state. By intentionally choosing to make the sexual act itself sterile by any means is the issue. So in choosing to take contraceptive chemicals, when the sexual act takes place the chemical is also involved in making the human body sterile during the act. This is clearly in a different category than abstaining from the sexual act altogether. It is not a sin not to have sexual intercourse with your spouse for a period of time. So one involves making the sexual act itself sterile by poisoning the body artificially, and the other involves simply choosing not to engage in the sexual act at a certain period of time. Despite the intention, these are two different means altogether.
Now looking to the morality of choosing not to engage in the sexual act at a certain time to avoid conception is a further issue that must be examined. I think there is a misconception involving NFP and what it entails. We then define NFP (Natural Family Planning) in the following manner.
If, then, there are serious motives to space out births, which derive from the physical or psychological conditions of husband and wife, or from external conditions, the Church teaches that it is then licit to take into account the natural rhythms immanent in the generative functions… [Pope Paul VI, Humanae Vitae 16]The first issue here is that this NFP can only be enacted for serious or grave reasons. So Catholics are not free to engage in NFP for trivial, selfish reasons. This worldly mentality would be contrary to the giving of oneself for the primary blessing in marriage, procreation. Secondly, the Church teaches that the sexual act itself cannot be rendered sterile by any artificial means, so this would negate the use of artificial birth control. "Since, therefore, the conjugal act is destined primarily by nature for the begetting of children, those who in exercising it deliberately frustrate its natural power and purpose sin against nature and commit a deed which is shameful and intrinsically vicious." (Casti Connubii) Artificial means used on the body is only acceptable when the intent is to restore the body to its proper working order, not to hinder or destroy it. So obviously medical treatment to restore the body to its natural working order would not fall into the same category. I state this because I have had objectors bring this issue up. In contrast, when the married couple chooses to abstain from intercourse no sexual act is happening so there is no hindrance to the sexual act as there would be if one had one used a condom or made the body sterile with chemicals. This again clearly points to a distinction in the acts themselves. Using NFP then would still allow the human bodies to function as they ought when the conjugal act eventually happens. Even though the couple has decided due to severe reasons such as medical, severe economical, psychological, etc., to abstain from the act, they never intentionally render the act sterile when it does take place.
So I would argue here that the use of artificial contraception and avoiding the conjugal act are completely different acts which affect the marriage and the bodies of the persons in a completely different manner. It is suggested in the question of the poster that, "They both are not full proof but originate from the same desire." Yes they both are not infallible and it is possible for these acts to originate from the same desire since one using artificial birth control could desire to use it because of the same grave reasons. The issue then would be the means by which the couple is trying to avoid conception. The licit means to avoid the pregnancy would be to abstain during the fertile periods until the time of the serious reason has ceased. The illicit means would be to poison one's body with chemicals to render the act completely sterile, or to use some artificial barrier to prevent conception making the act sterile. I would also argue that the mentality is different being that one couple has at least chosen to be open to God in the giving of each other in the natural conjugal act, while the other has chosen to physically deform the body to change the nature of the conjugal act itself. As Father John Hardon points out, "Our natural tendency is to get sexual pleasure from another person without assuming responsibilities... Marital love must be a love that sacrifices." St. Thomas Aquinas states in an even a more direct manner, “Those who use poisonous drugs (venena) for sterility are not spouses but fornicators...(Conjugal relations) are not to be changed to a use contrary to nature." I could go on and look at the nature of virtue in marriage as well as the person being created in the image and likeness of God, and the nature of true love in marriage. This would take another article to delve into that side of the issue. An understanding of the Natural Law would also help understand this prohibition, which I don't have the time in this article to elaborate on. I would advise that the encyclical 'Casti Connubii' be read to gain a more fuller understanding of marriage and the conjugal act, and I would recommend reading Thomistic sources for understanding the Natural Law.
The main point in answering the post here is that the two acts, one of abstaining from the sexual act, and the one of rendering the act sterile by some artificial means are not synonymous. There is no intrinsic sin in abstaining from the conjugal act, there is intrinsic sin in rendering the conjugal act itself sterile, it is contrary to nature, the way God created us. NFP when done legitimately still respects human nature as it is designed by God, while the other does not. In addition, the mentality and intent can be sinful depending on the reasons the couple is choosing to abstain. So for instance, if the couple wants a third TV for their bedroom and decides to avoid the conjugal act for the purpose of obtaining the TV, this would be disordered and out of bounds for the legitimate practice of NFP. I hope this answers the question. I know I have not covered all objections here, but I hope this gives the essence of the differences that were in question.
In order, however, that amongst men of every nation and every age the desired fruits may be obtained from this renewal of matrimony, it is necessary, first of all, that men's minds be illuminated with the true doctrine of Christ regarding it; and secondly, that Christian spouses, the weakness of their wills strengthened by the internal grace of God, shape all their ways of thinking and of acting in conformity with that pure law of Christ so as to obtain true peace and happiness for themselves and for their families. (Casti Connubii)