Although I cannot judge a particular couple’s selfishness, I can say that periodic continence or Natural Family Planning (NFP) should be a rare occurrence, especially among the first world countries capable of supporting children, and it definitely should not be promoted for all married Catholics.
[emphasis mine] I read your whole post and I do get where you are coming from. I really do. But you are making a subjective judgment here and in other parts I snipped for brevity. (Brief? Yeah me, be brief? Right!)
In your opinion it
should be rare. In your opinion you are saying it isn’t rare. It is rare. I am the only one of my (Catholic) friends with bad health who needs to practice NFP. But on topic to this thread…periodic continence is a GREAT thing to practice in marriage.
As I stated in the other thread (the one that got locked

) charting is completely
neutral. There is no reason whatsoever to indict couples for understanding their mutual fertility. No document in Church history has
ever said that understanding fertility is even part of the problem of the culture of death. My charts and my thermometer have nothing to do with this discussion. My knowledge of my fertility is a good thing.
What the documents in question are saying is that a couple must have just reason (or serious, or grave,) to purposefully make
exclusive use of the infertile phases. That is without question. Any and every couple using NFP will agree with that. If they don’t, then we can discuss ways to counter their contraceptive mentality. A couple who remains ignorant of fertility is not more holy than a charting couple. But a couple who is generous in their circumstances IS holy. That means my small garden with 2 blossoms or a large garden are both holy given our circumstances.
The documents advising against a set number of children are often about an
early decision to limit the number of children. This is a problem made worse by total celibacy in marriage. Period continence keeps that discussion alive. Do we still have serious reason? Have the circumstances changed? Is our health/financial/other children etc. and so on, reason still serious? For a couple to enter marriage with a set number of children in mind is one of the things couples are cautioned against. This is on both ends of the spectrum, many or few children.
Periodic continence IS trusting in Providence. With periodic continence you plan for each baby at a time. 1 Cor 7:5 says “for a season” in your translation. (A translation I fall in love with more every day, BTW.) What is a season? Three months? Winter, Spring, Summer, Autumn. One month? A lunar season? Is it like my health, which waxes and wanes? Is it a season fertility-infertility? ‘Season’ in most translations means ‘for a time’ or ‘during change.’ Those definitions apply to fertility, pregnancy, and menopause.
Yes, I totally 100% agree with you that limiting of family size
should be rare. But making that happen is tough on some of us. If you know someone who can cure my health struggles, please point the way. I will NOT stop practicing periodic continence because it brings blessings to my marriage…but I would stop practicing it during fertility.