He recently sent out an article titled, "An Evaluation of Natural Family Planning" (note: opens as a PDF) in which he attempts to prove that NFP and certain forms of contraception are no different from one another (and thus the Catholic Church is wrong to teach that all contraception is immoral). To his credit, he condemns contraception that is potentially abortive, and for that I commend him. However, his points are illogical and unpersuasive, and I sent him the below e-mail in an attempt to point out some of the flaws in his argument.
Dear Dr. Mizzi:
I read this document and found several aspects of it puzzling.
For example, this excerpt:
The basic moral difference between periodic abstinence and artificial methods of birth control is given in Humanae Vitae, 16: „In the former the married couple rightly use a faculty provided them by nature. In the later they obstruct the natural development of the generative process.‟ The basic difference is not in the motive – parents can use either method to avoid pregnancy for some just reason – but in the means to reach that same goal. Since nature already provides a faculty to prevent pregnancy, and since it in certain circumstances it is desirable and good to avoid pregnancy, the Catholic objection to contraception is unsustainable.
I don't understand how anything you say in this paragraph leads to the conclusion that "the Catholic objection to contraception is unsustainable." Pope Pius XI said in Casti Connubii (all emphasis mine):
54. But no reason, however grave, may be put forward by which anything intrinsically against nature may become conformable to nature and morally good. 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.
56. ... Any use whatsoever of matrimony exercised in such a way that the act is deliberately deprived of its natural power to generate life is an offense against the law of God and of nature, and those who indulge in such are branded with the guilt of a grave sin.
Note the words "deliberately frustrate" and "deliberately deprived." Couples who use NFP are doing nothing to deliberately frustrate the marital act. In fact, it is impossible to do so, for no act is being performed -- an act is being abstained from, but that is not the same as engaging in the marital act and taking steps, either in anticipation of the act or after it has taken place, to deliberately frustrate the natural power and purpose. Condoms, for example, deliberately frustrate the natural power of the marital act by preventing the sperm from entering the woman's vaginal canal. With NFP, however, nothing artificial (like a barrier of latex) is preventing conception from occurring naturally. The only thing that MAY prevent conception is the fact that ovulation either has not yet occurred or has already taken place, and that naturally-occurring cycle was put in place by God and not altered by either the husband or the wife. Given this distinction, I really don't see how you can logically say that condoms are no different from NFP, and your article doesn't really specify either. (Also, your article fails to mention that NFP can also be used to ACHIEVE pregnancy -- my husband and I have used it several times for that purpose. What other method of birth control is also used to ACHIEVE pregnancy?)
I do, however, commend you for condemning those means of contraception which are potentially abortive -- many of your Protestant brethren do not do so.
In brief, there is no essential difference between periodic abstinence and artificial methods of birth control. Both can be used for exactly the same purpose. Moreover there is no moral difference between the means employed, whether „natural‟ or „artificial‟, since it is right to suppress normal body functions for the right reason, and in any case, nature itself imposes limits on human fertility.
You're partially right with this statement in that spacing births is not an objectively evil end. However, I do disagree with you that the means are exactly the same. With condoms and other forms of contraception, couples seek to deliberately frustrate, through artificial means, the two dual purposes of the marital act (unity of the spouses, and procreative capability). With NFP, no such deliberate frustration is happening. The couple is merely taking advantage of the woman's natural periods of fertility or infertility in the cycle created by God (who could have chosen to make women fertile 24/7, but did not). There is no deliberate frustration going on as there is with contraception, because each and every act is open and unhindered to the possibility of conception, however remote that possibility may be.
I also find your comparison to appetite suppressants to be weak. If a person is using an appetite suppressant, it is because s/he is attempting to suppress an unnaturally or abnormally large appetite. (Also, one should not be using appetite suppressants if their appetite is healthy; rather, they should simply abstain from unhealthy or high-calorie foods as befits the virtue of temperance.) As you note in your piece, the Catholic Church has no problem with using drugs or medicines in order to restore heath or cure an illness. Contraception, when used for the purpose of spacing pregnancy, is not being used to cure a disease or health problem; rather, it is being used to subvert normal, healthy, functioning fertility. NFP, on the other hand, allows couples to space births by practicing periodic abstinence, which is praised by St. Paul (1 Corinthians 7:5).
You also state in your article that "the second purpose [procreation] is not always present in nature and it should not be forced on the intent of the conjugal act."
It's interesting to note that this is the exact same argument many "pro-choice Christians" use to justify abortion. They argue that since embryonic or fetal death occurs in nature via spontaneous abortion (i.e., miscarriage), we are fully justified in aborting children via induced abortion. It seems, in order to be logically consistent, if you use this "not always present in nature" argument for contraception, you must also use it in favor of abortion - yet your article seems to indicate you consider abortion immoral. How do you reconcile this logical contradiction?
Also, you state, "The facts of history prove that the position of the Catholic Church has also changed dramatically" but none of the facts you present prove this statement. The Catholic Church has never taught as official doctrine that it is objectively evil or immoral to space pregnancy, only that it was wrong to deliberately frustrate procreation (e.g., by obtaining "potions of sterility" or by spilling one's seed on the ground, like Onan). The Church has consistently taught, as St. Paul did, that mutual abstinence has been acceptable as long as both spouses consent and there is no danger of either falling into lust and being tempted as a result of said abstinence.
Given that the Church has never taught that spacing pregnancy in and of itself was objectively evil or immoral, Her teachings did not "change dramatically" at all. Once scientists learned that it was possible to discern a woman's potential fertility via outward signs, the Church continued to teach that periodic abstinence was acceptable for spacing births, and that it was not a sin to practice periodic abstinence in conjunction with discerning a woman's natural fertility or infertility based on outward signs. See Fr. Brian Harrison's excellent article, "Is NFP A Heresy?" for a more thorough explanation.
Moreover, given that every Christian denomination taught that all contraception - abortifacent or otherwise - was objectively immoral until 1930, it seems that Christian denominations who currently teach that contraception is acceptable in any form either believe that God changed His mind or that God allowed Christians to believe and teach false doctrine for over 1,900 years. Which of these is your position? Your article doesn't say.
My friend Leila wrote an excellent blog post on this topic which you may find informative. Another excellent, thorough article is Dr. Janet Smith's Contraception: Why Not? I hope you take the time to read and consider the points made in both.