I just want to respond to a couple of points in Kelly’s excellent letter-
Unless I missed it, I don’t think that anyone said that it’s impossible for someone to take an objectively good thing and twist it into something selfish. The question is whether breastfeeding with the intent to space children is twisting at all.
You are correct- using the word “impossible” was wrong- what I meant to point out is that some of the remarks here seem directed towards the idea that using breastfeeding with the sole intent (no mixed motivations) of prolonging infertility is almost never done, by any woman. Or if it is, it would be “very rare.” In this case I would have to disagree, based on the individual nature of each and every union, and each and every choice. We simply cannot know that, and neither does it absolve us of the responsibility to enter into any idea of child spacing with prayerful and prudential judgement, and with guidance of a trustworthy confessor.
in his “Address to Midwives on the Nature of Their Profession,” found here:
papalencyclicals.net/Pius12/index.htm Pope Pius XII had this to say:
"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 tile full their sensuality, can only be the result of a false appreciation of life and of motives foreign to sound ethical principles." (my emphasis added)
So-I’m only advocating for what the church has
always taught us- that NFP should be used for serious reasons since we are to view the conception as pure gift, not burdensome, not agony, not a terror. Check out this website, if you are interested in reading an article on the topic.
cantuar.blogspot.ca/2012/02/you-can-only-use-nfp-for-grave.html
Now I realize that breastfeeding and period continence are two different things- however we are speaking in this case, of an extended form of breastfeeding which may- please note-
may -fall under the same guidelines. I for one, am not
certain it does, I’d have to do more research- so that’s why I’m advocating for prayerful discernment in the using of such a method - and the Church does instruct us that whenever we look to enjoy (or in some cases -especially tired ones- allow our spouse to enjoy!) the sensual part of our union in times of infertility we should do so with prayer spiritual direction and an attitude of caution and even a certain type of regret at the impossibility of conception… I think it’s really important for us to remember this, since we live in a time where the conception of many children is generally considered burdensome, slightly crazy, even selfish- and we may feel that we are offering God something by accepting more children rather than rejoicing in what He has so lovingly offered us. I think that you and I- everyone reading- is affected, more or less, by that cultural mentality we live with, day in, and day out.
How could wanting what God wants for us be compared to giving to a poor man for our own glory? God doesn’t want us to give to others just so that we can look good.
Again this was a poor choice of words on my part- it was intended only as a logical example, to give a correlation between a similar idea of motives- not to insinuate that women may breastfeed for self-glorification or something like that- that wasn’t the intent of my example. Let me use another to clarify what I meant: in the case of marital relations both means (physical pleasure bonding, release, etc) and ends are goods, per se, this does not mean, however, that marital relations are rarely, if ever, entered into with a spirit of self-orientation by either, or both, spouses. Not necessarily. Do we know if they ever are, by any couple? That is something that we really can’t say, but we can have some idea based on our own experiences with sin, whether this is a danger in this world, or not. And then, we can pray before we enter the carnal junction so that we don’t fall into sin- and God will not fail us. But we should bear in mind, John 1 verse 8-10 says that any man who considers himself to be without sin, is deceiving himself- so I think we need to tread prayerfully in the area of reproductive choices, child-spacing, etc- such a serious, serious responsibility- and not just assume that when we decide to limit our family size through natural methods, we do so without sin, based on the grounds that it’s natural and the means and ends are both good. There is a fine line between crossing over into the area of actual sinfulness- especially with breastfeeding as a “method” - I’ll grant you that- and if there are any sides in this argument (which may be arguable in itself
) it is only, it seems to me, that some of us advocate for a cautious and prayerful attitude when it comes to the use of
any method at all of NFP or child spacing- and some, it appears, do not think it is possible for sin to be involved in such decisions, under the premise that a child is being fed. I must continue below because my post is too long-
It does become a very individual thing though- not every woman is made in exactly the same way. In my case, my cycle returned remarkably quickly in spite of the fact that my babies nursed like little marsupials until they were what most people thought was " a ridiculous age." 
The fact that breastfeeding your children this way means a later return of fertility than what most women expect is unknown to most people (including many doctors), hence Kippley (and others, but I’m not as familiar with them) writing books about how it works and why it’s part of God’s plan for women having children.
