I understand the church’s position. My whole point is that the permissive part of NFP does not appear to dovetail with the very nice consistent natural law arguments that can be made to support the rest of the church’s teaching on sexuality. If your point is this is an “all faith, no reason” situation, then so be it. As I mentioned at the outset, I am not catholic but seriously studying the faith and talking to priests about converting. Presumably thinking about the underpinnings of the faith is reasonable instead of simply saying that is what the church teaches, so don’t think about it.
Also, the point about why there is no restriction on infertile period sex in the bible is a bit of a straw man. No one can predict with certainty that having sex precisely at this moment or that moment will result in conception. The problem I have is intent. If a couple practicing NFP is doing everything in their ability to enjoy the pleasure of sex but avoid the consequences it is hard to justify that on a natural law / reason basis and square it with all of the rest of the church’s teaching. On the other hand, if a couple simply doesn’t focus on cycles and has relations when the mood strikes, that seems completely fine even if sometime they are having sex at low fertility times. If their honest intent is that we aren’t going to worry about it, and let God decide then that seems completely fine. One of the great things to me about the Catholic Church is the focus in self mastery and control. If you honestly don’t want another child, can’t afford a child, or whatever the reason is, then in my own mind I have to really question whether God is asking me to also forego the physical gratification of the act and exercise some personal restraint and discipline instead of trying to separate the two.
Have you read this from Pope Pius XII? It provides some answers to your questions.From Address to Midwives:
The reason is that marriage obliges the partners to a state of life, which even as it confers certain rights so it also imposes the accomplishment of a positive work concerning the state itself. In such a case, the general principle may be applied that a positive action may be omitted if grave motives, independent of the good will of those who are obliged to perform it, show that its performance is inopportune, or prove that it may not be claimed with equal right by the petitioner—in this case, mankind.
The matrimonial contract, which confers on the married couple the right to satisfy the inclination of nature, constitutes them in a state of life, namely, the matrimonial state. Now, on married couples, who make use of the specific act of their state, nature and the Creator impose the function of providing for the preservation of mankind. This is the characteristic service which gives rise to the peculiar value of their state, the bonum prolis. The individual and society, the people and the State, the Church itself, depend for their existence, in the order established by God, on fruitful marriages. Therefore, to embrace the matrimonial state, to use continually the faculty proper to such a state and lawful only therein, and, at the same time, to avoid its primary duty without a grave reason, would be a sin against the very nature of married life.
Serious motives, such as those which not rarely arise from medical, eugenic, economic and social so-called “indications,” may exempt husband and wife from the obligatory, positive debt for a long period or even for the entire period of matrimonial life. From this it follows that the observance of the natural sterile periods may be lawful, from the moral viewpoint: and it is lawful in the conditions mentioned. If, however, according to a reasonable and equitable judgment, there are no such grave reasons either personal or deriving from exterior circumstances, the will to avoid the fecundity of their union, while continuing to satisfy to the full their sensuality, can only be the result of a false appreciation of life and of motives foreign to sound ethical principles.
~
Address to Midwives, Given by His Holiness Pope Pius XII, 29 October 1951