P. Francesco di Felice, an Italian priest who worked in the Vatican Secretariat of State during the pontificate of Pope Paul VI, recounted the incredible story behind Humane Vitae, the encyclical that in 1968 would become the most answered in history of the church.

To write the encyclical humane Vitae letter on birth regulation, Pope Paul VI collected the work initiated by St. John XXIII who created the "Commission for the Study of population, family and birth problems" to have a better understanding of the Action of contraceptives, something that at the time was not well known.

The Commission wrote a report for Pope Paul VI, which was leaked to the media, and increased the pressure on it. In essence, the report was divided into two parts: the opinion of the majority supporting contraception and its response to the minority; And the minority's view that contraceptives should be rejected according to the teaching of the church.

In statements, Father Di Felice explained that "Paul VI took these two documents, that of the majority and the minority, took them to his private chapel and spent the whole night in prayer, wondering what should I choose for the good of souls?"

"Then, in the light of Dawn, at the first lights, it came as enlightenment, a firm decision, as if the Holy Spirit comforted him, and said". This is what I have to choose! And it was a great choice, because if we admit the use of pills that alters the mystery of life, the natural course would be altered and would have been a disaster.

In fact, as a result of the reaction it would answer that it received the document at world level, even of important theologians, the Holy Father would not rewrite an encyclical in the remaining 10 years of his pontificate which concluded in 1978. In the previous five years he had written 7 encyclicals.

For all this, the then Secretary of state, Cardinal Agostino Casaroli, would later say that "the morning of July 25, 1968 Paul VI celebrated the mass of the Holy Spirit, asked for light from above and signed: he signed his most difficult signature, one of his most glorious signatures. He signed his own passion".