Well, that stricture isn't anything I have heard the magisterium decide. I have no doubt you are much better informed than I am about this issue and so I wonder if you can cite a decision taken that supports that statement.
. I am not being arguementative, I am a big fan of yours. It just seems to me that as God has both an active and permissive will, that includes a lot of wiggle room (I was gonna excise that phrase but when one discusses sex it is nearly imposible to avoid double entendres).
I am sure you know that as Karol Wotyla, the Pope wrote a tome on sex (I let a friend read my copy and never got it back) and he spoke about that natural infertile time when it certainly is permissible for one to have sexual congress (another one, I know) and not be engaged in anything opposed to the will of God.
It is my understanding that is what Natural Family Planning teaches also.
I think I must be misunderstanding you and I look forward to your reply. Please keep up your great work...
Yet even this practice is open to life, it does not suppress or obliterate fertility, it accepts it and embraces it fully. And as our first born aptly illustrates, it is open to God's Will if He desires us to conceive at a particular time. My wife ovulated on the 7th day of her cycle when Mikey was conceived, something that never happened before or since. And it happened while we were on pilgrimage to the Basilica of the National Shrine of the Immaculate Conception in Washington DC, on the Feast of the Immaculate Conception. If we had been using artificial methods Mikey would not be here, and our lives would be radically different.