3. This new state of things gives rise to new questions. Granted the conditions of life today and taking into account the relevance of married love to the harmony and mutual fidelity of husband and wife, would it not be right to review the moral norms in force till now, especially when it is felt that these can be observed only with the gravest difficulty, sometimes only by heroic effort?
Moreover, if one were to apply here the so called principle of totality, could it not be accepted that the intention to have a less prolific but more rationally planned family might transform an action which renders natural processes infertile into a licit and provident control of birth? Could it not be admitted, in other words, that procreative finality applies to the totality of married life rather than to each single act?
A further question is whether, because people are more conscious today of their responsibilities, the time has not come when the transmission of life should be regulated by their intelligence and will rather than through the specific rhythms of their own bodies.
Paragraph 3 makes note of some “new questions” that are brought upon the Church’s teaching by the modern world. Those who ask these questions are trying to find good reasons to justify the artificial control of birth, that one cannot judge until the “big picture” is looked at. After all, hasn’t man become sophisticated enough that he can decide how many and when children are to born?
This and the previous paragraphs show that the Church is very much aware of the challenges that husbands and wives face in living their vocations. But the Church also reminds us that the “moral norms” are those that have always been in force and with good reason, that they are observed “only with the gravest difficulty”, and that fidelity takes “heroic effort” on the part of both husband and wife. It is that “heroic effort” that allows one to become a saint.
1catholicsalmon 
sonicsiesta
/ March 28, 2012Not understanding the point of this paragraph. I am feeling that it is very vague or I don’t understand what it is trying to get across. More explanation would be welcome
1catholicsalmon
/ April 1, 2012Basically, Paul VI is saying that the Church knows that there are great challenges that husbands and wives face in having children and raising a family. The Church is not oblivious to the difficulties that are out there. But while the world says that contraception is something that couples can use to make things easier for them, the Church says that contraception destroys marriages and lives. This is why every marital act must be open to life.