As follows from the previous note, not using man-made contraceptives entails a “pro-life” attitude, a state of mind that affirms humanity. It’s a healthy philosophy of life or ideology, as wholesome as libertarianism is compared to evil conservatism and stupid left-liberalism.
When John Paul II mentioned the culture of death with respect to contraceptives, he is to be understood in a sense different from such a culture with respect to abortion. This is because for birth control, children are never conceived in the first place and therefore, cannot die. The Pope was referring to the death of the human race.
Perpetuation of the species is a different thing altogether from individual search for happiness. Sometimes the two are in conflict, and when such is the case, the conflict must be wisely resolved.
It is certainly true that any single person’s decisions regarding his own procreation cannot be held responsible for the fate of the human race. If we are to go extinct, this particular Smith was not the cause of it. Therefore, again, using NFP in married life is a matter of piety, of something given to God according to justice, in God’s capacity as an authority over His most valuable creation, the human race. Smith will not bring about the continuation of our species, but he will at least practice what he preaches.