From Fr. Z's blog you can read the truth about the lies concerning artificial birth control and nuns by pressing these sentences:
It’s not an urban legend, it’s a LIE: Paul VI did NOT give permission to nuns to use contraceptives.
These are my comments: I can remember when I was a teenager and older that my Protestant anti-Catholic friends (they didn't think they were anti-Catholic, they thought they were evangelizing me by taking me away from the Catholic Church and thus saving me) used the same example that Pope Francis used in his infamous interview above the Atlantic on the way to Rome from Mexico.
That example as the Pope and my anti-Catholic friends used, is that Blessed Pope Paul VI allowed nuns to use artificial birth control in Africa. My anti-Catholic friends didn't make the distinction, though, that the reason the pope allowed it was because of the potential of rape leading to conception. My anti-Catholic friends made is sound like the nuns were routinely having consensual sex. You see where they were going.
I remember at the time asking my parish priest about their example and he said they were anti-Catholic and lying. I believed my priest and not my anti-Catholic friends who routinely used distortions to try to get me to join their denomination.
But now, Fr. Z makes clear that Blessed Pope Paul VI allowed no such thing! However, evidently this anti-Catholic lie is legend around the world and even Pope Francis had heard of it thinking it was true and used it as an example of allowing artificial birth control in dysfunctional/dangerous situations.
That's the danger of speaking off-the-cuff and not doing one's homework and it is scandalous for a pope, any pope, given the nature of his authority in the Church, to do so.
Thus, Pope Francis extremely and I mean extremely off-the-cuff remarks concerning the use of artificial birth control by married couples engaging in the licit use of the marital act in order to prevent what should happen naturally as natural law codifies, and using a false example, a lie, to back it up is simply irresponsible.
With that said, either intentionally or unintentionally, Pope Francis has pulled the thread that holds together all that the Church teaches concerning Natural Law and thus this will aid and abet those progressive liberals in the Church who want not only to change the Church's teaching as confirmed by Blessed Pope Paul VI in Humanae Vitae, but also as it concerns same sex marriage and women being ordained to Holy Orders.
We are now on the way to becoming what the Anglican Communion is especially its Protestant Episcopal Church in the USA unless there is a clear repudiation by the pope himself about this off-the-cuff remark using a lie to back it up.
Of course, most thinking Catholics know that even if the urban legend that my anti-Catholic friends told me about decades ago were true, for nuns to protect themselves from unwanted conception due to the real possibility of rape which isn't the marital act, by the way, is not the same as those who are married and enjoy the right to the actual marital act using contraception to prevent the conception of a child that might be handicapped in one way or the other.
There are many married men and women who could conceive a child with a genetic disorder inherited from one or the other. Is there now blanket approval from the Church to use artificial birth control to prevent a child from being conceived who has a genetic disorder inherited from one of her parents?
These are pastoral situations best suited to the realm of the secrecy of the confessional and pastoral advice which is never doctrine or dogma.
I would not be surprised at all if Cardinal Mueller and other cardinals issued statement concerning what Pope Francis has said and the potential damage His Holiness could cause to orthodox Catholic teaching concerning natural law.
I would prefer for Pope Francis to issue a statement in writing clarifying Church teaching in this regard. I hope and pray that His Holiness will.
Of course, if a pope teaches that which is false, a Catholic must not accept that as a teaching of the Church and see it only as an opinion.