Then, this love is total, that is to say, it is a very special form of personal friendship, in which husband and wife generously share everything, without undue reservations or selfish calculations. Whoever truly loves his marriage partner loves not only for what he receives, but for the partner's self, rejoicing that he can enrich his partner with the gift of himself.

Again, this love is faithful and exclusive until death. Thus in fact do bride and groom conceive it to be on the day when they freely and in full awareness assume the duty of the marriage bond. A fidelity, this, which can sometimes be difficult, but is always possible, always noble and meritorious, as no one can deny. The example of so many married persons down through the centuries shows, not only that fidelity is according to the nature of marriage, but also that it is a source of profound and lasting happiness and finally, this love is fecund for it is not exhausted by the communion between husband and wife, but is destined to continue, raising up new lives. "Marriage and conjugal love are by their nature ordained toward the begetting and educating of children. Children are really the supreme gift of marriage and contribute very substantially to the welfare of their parents." (8)

 
Responsible Parenthood

10. Hence conjugal love requires in husband and wife an awareness of their mission of "responsible parenthood," which today is rightly much insisted upon, and which also must be exactly understood. Consequently it is to be considered under different aspects which are legitimate and connected with one another.

In relation to the biological processes, responsible parenthood means the knowledge and respect of their functions; human intellect discovers in the power of giving life biological laws which are part of the human person. (9)

In relation to the tendencies of instinct or passion, responsible parenthood means that necessary dominion which reason and will must exercise over them.

In relation to physical, economic, psychological and social conditions, responsible parenthood is exercised, either by the deliberate and generous decision to raise a numerous family, or by the decision, made for grave motives and with due respect for the moral law, to avoid for the time being, or even for an indeterminate period, a new birth.