To: WorldviewDadIf my children would literally starve if my wife were to get pregnant, it is morally licit to space children until I could afford to feed them.
NFP would be a morally licit way to achieve this necessity.
But artificial birth control is intrinsically evil. It can never be morally licit to have recourse to artificial contraception.
So to answer your question, the INTENTION in having recourse to EITHER artificial family planning OR "natural" family planning could be illicit or licit. One may be sinful, one may not.
However, the method itself, in the case of artificial birth control, is intrinsically illicit, i.e. regardless of intent is it gravely sinful.
However, NFP itself is morally neutral. It becomes morally illicit when the intention itself is illicit.
4 main reasons for having recourse to NFP.
1--Physical/ mental health---a pregnancy could kill you or so physically impair you as to prevent your fulfillment of your duties in your state in life---NOT because of a widening waste-line or drooping skin! Or psychological health, i.e., mom would literally have a nervous breakdown if she became pregnant---not because she "just couldn't stand being home with the little kids all day without the personal fulfillment of her professional job..."
2--Financial constraints---your child will starve if you have another. Wanting a bigger house or designer SUV just does not cut it!
3--work on the mission fields by one or both spouses that would preclude having children temporarily
4--active persecution or war---i.e., you or your child likely to die by coercive abortion, in concentration camp, in acts of war, etc.
Clearly we say these reasons must be SERIOUS, not trivial. Only the couple and their confessor can truly decide what truly constitutes grave reason.
We've had couples sit through my talk on this subject and literally say, "Gee, we thought we were being good Catholics just for deciding to use NFP. Now we realize we don't even have grounds for recourse to NFP," then tell us a month or two later they're pregnant.
NFP vs Contraception
Spacing children may be a desirable goal that does not violate God's laws in certain serious situations such as those outlined above. But the means of achieving the goal differ.
One is intrinsically evil (abortion, abortifacient contraception, barrier methods, sterilization) while one is morally neutral (Natural Family Planning.
In one, an act is performed (sex) but its natural outcome is artificially foiled.
In the other, no act is performed (simple abstinence during fertile times) so there IS no act, therefore the practice is morally neutral.
It is then the intention of using NFP that constitutes its relative moral licitness or illicitness.
If NFP is used in a selfish manner, it too can be sinful.
If it is used only in grave circumstances, it is not sinful.
The difference is real.
Dieting (decreasing caloric intake, the "act" of NOT eating) is a moral and responsible means of losing weight to maintain the body's health.
Bulimia (the ACT of eating, them vomiting) is rightly called an eating DISORDER.
An ACT is performed (eating in this case) and its natural outcome (nutrition) is foiled by expelling the food from the body.
Likewise contraception is a disorder. An ACT is performed (sex) and its natural outcome (procreation) is foiled by expelling the sperm or egg or both (abortifacient contraceptives) from the body.
Contraception is to NFP what Bulimia is to dieting.
But just as dieting can be misused (anorexia) so too can NFP be misused in a sinful manner
From this post, it seems that practicing NFP is a sin, unless you're in one of these four situations:
"1--Physical/ mental health---a pregnancy could kill you or so physically impair you as to prevent your fulfillment of your duties in your state in life---NOT because of a widening waste-line or drooping skin! Or psychological health, i.e., mom would literally have a nervous breakdown if she became pregnant---not because she "just couldn't stand being home with the little kids all day without the personal fulfillment of her professional job..."
2--Financial constraints---your child will starve if you have another. Wanting a bigger house or designer SUV just does not cut it!
3--work on the mission fields by one or both spouses that would preclude having children temporarily
4--active persecution or war---i.e., you or your child likely to die by coercive abortion, in concentration camp, in acts of war, etc."
Honestly, there are very few people in modern America that would fit into any of these categories. There may be a few people in category 1 and a tiny amount of people in category 3, but I see practically no present-day Americans that fit into categories 2 and 4.
But from reading other sources, it seems that NFP is fine no matter when and these conditions are rarely, if ever, mentioned.
1) Some religions consider the consumption of pork to be a grave sin, and have strict dietary restrictions. More likely than not, this is just long standing wisdom codified in religious terms to improve the health of the population. Likewise, prohibitions on contraception are there to increase populations and have more to do with raising armies and building workforces than anything else. They are for societal self preservation.
2) Contraception which does not destroy lives is not inherently evil. It is morally neutral. Having children is good. Not having any is not evil. If it were, then those who take a vow of celibacy would would be guilty of grave sin
3) The natural order of life is to get wet when it rains, die from infectious diseases, etc. and yet we subvert this by wearing raincoats and injecting ourselves with potions of protection, etc. These therefore must be evil.
4) Contraception is to NFP as flowers are to Irises.