One of the most unpopular decisions any pope has ever made was the decision of Paul VI to forbid artificial contraception. I have the feeling that he may not have totally understood his decision but the Holy Spirit knew what He was doing.
When you look some 40 or 50 years later you see the consequences of ignoring his teaching. Breast Cancer has increased over 600 % and many oncologists believe the Pill is involved. Marriage has basically disintegrated.
Most people don’t realize it but there was an alternative. Natural Family Planning. I first learned of it in a Human Anatomy Course at Union College, a public college in 1977. It utilizes the same techniques that doctors used in fertility clinics only they are used to avoid conception rather than facilitate it. It requires discipline, communication and collaboration between a couple. According to my professor it was as effective as the Pill without negative side effects. There were positive side effects of the work and collaboration needed. Natural Family Planning marriages have a success rate of over 90% far better than other marriages.
Maybe the pope didn’t know what he was doing but the Holy Spirit who guides the pope did.