Roma locuta; causa finita est. (Rome has spoken, the matter is settled.)

If Paul VI released an immoral encyclical, then Jesus lied when he said “the gates of hell shall not prevail over [the Church]“, and there is no sense in being Catholic anymore.

This also means that Pius XII issued immoral instructions to the Italian midwives when he told them to instruct married couples in the (then state of the art) rhythm method.

Church acknowledgement of the licitness of NFP goes all the way back to when it was first theorized in the 1850s.

http://www.rtforum.org/lt/lt103.html

This 1995 clinical study verifies Casti Connubii’s claim that “any use WHATEVER of MATRIMONY exercised in such away that the act is deliberately FRUSTRATED IN ITS NATURAL POWER TO GENERATE LIFE is an offense against the LAW of God AND OF NATURE.” Or put more succinctly, this 1995 clinical study verifies that NFP is clearly against the LAW OF NATURE (as warned about in Casti Connubii) because this immoral practice has the ability to kill innocent unborn babies through unnecessary miscarriages. Further, it can be extrapolated that if NFP can cause miscarriages in some situations, in may also cause serious health problems in NFP babies that survive birth; namely birth defects, handicaps, genetic defects, and general health problems.

Therefore, based on Casti Connubii, the only morally licit use of NFP is REVERSE NFP where women find the most fertilepoint of their cycle in order to ensure healthy healthy ovums (eggs) that will more likely result in healthy robust human embryos when those eggs become fertilized and, ultimately, more likely healthy children when they are born. However, the use of NFP to deliberately prevent pregnancy, I believe,
would be analogous to the hypothetical situation where a farmer purposefully sows seeds in a field in which the crops had never been rotated. Obviously, by not rotating the crops, the nutrient rich soil would have been depleted, resulting in a disastrous harvest of sickly, unhealthy and withered crops; or no crops at all. Obviously, both circumstances are against
the NATURAL LAW due to the possible negative consequences that could result.

Based on the morally sensible, Casti Connubbi, then, if married couples want to get to heaven, they should attempt
to have as many children as they can, unless necessity dictates, otherwise; such as the health of women and financial burdens. If these necessities do arise, Casti Connubbi only allows for married couples to space children out through PURE CONTINENCE. You should also pray for grace from God and
even fast if possibly in order to practice SUCCESSFUL, PURE CONTINENCE under those trying circumstances. Remember, Jesus never said following Him would be easy; instead, He said; “TAKE UP YOUR CROSS AND FOLLOW ME!”

According, to the still authoritative 1930 encyclical, Casti Connubii, the primary purpose of the marital union is always to be procreation (intent to have children) and the secondary purpose, the conjugal act. However, with both Natural Family Planning and artificial birth control methods, the OBVIOUS INTENT of all couples involved with these immoral practices, is to avoid having children while enjoying the evil fruits of the illicit (under these selfish circumstances) conjugal act, with all the abhorrent negative consequences. According to page 17 of Humanae Vitae, these abhorrent negative consequences (Humanae Vitae only applied these negative consequences to artificial birth control methods, but should have also applied them to NFP) of “SEX WITHOUT CONSEQUENCES,” include the lowering of the moral standards of couples; the men using their wives as sex objects; and building a false sense of autonomy from God. For these reasons, Humanae Vitae immorally claimed it was licit for Catholic couples to to use Natural Family Planning methods to space children out; and stood in direct contradiction to the 1930 encyclical, Casti Connubbii, on this subject. In fact, Natural Family Planning should be correctly styled, “NATURAL CONTRACEPTION,” since it is so effective (99.6 percent) in preventing pregnancy (more effective than most forms of artificial birth control methods).

The only real moral option for spacing children out for married couples is to use PURE CONTINENCE (i.e., COMPLETE abstinence from the marital union), as explicitly approved in the 1930 encyclical, Casti Connubii, at Paragraph 53, as being the only licit means, throughout the history of the Church, to space children out in cases of necessity (e.g., health of women; financial reasons; etc.). In fact, Joseph and Mary had to practice complete continence throughout their whole marriage to protect the perpetual virginity of the Blessed Virgin Mary.

Moreover, Casti Connubii, at Paragraph 56, states; “[A]ny use WHATEVER of MATRIMONY exercised in such a way that the act is DELIBERATELY FRUSTRATED IN ITS NATURAL POWER TO GENERATE LIFE is an offense against the LAW OF GOD AND OF NATURE, and those who indulge in such are branded with the GUILT OF GRAVE SIN (emphasis added).” Clearly, the use of NFP seeks to frustrate the natural power to generate life by having NFP women discover when they are the least fertile (i.e, post-ovulation) in order to prevent pregnancy. Instead, as correctly and morally approved by Casti Connubbi and as necessity dictates, married couples should only engage in PURE CONTINENCE in order to space out children; AND WHEN THEY DO ENGAGE IN THE MARITAL UNION THEY SHOULD HAVE THE CLEAR AND OBVIOUS INTENT TO POSSIBLY BRING ABOUT PREGNANCIES AND THE BLESSED CHILDREN THAT COULD RESULT, THEREFROM.