Good, then you should know that there is more than one purpose. Matrimony is not only about procreation.
285. Q. Which are the effects of the Sacrament of Matrimony?
A. The effects of the Sacrament of Matrimony are: first, to sanctify the love of husband and wife; second, to give them grace to bear with each other's weaknesses; third, to enable them to bring up their children in the fear and love of God.
-Baltimore Catechism, No. 2
Q. 1010. What are the chief ends of the Sacrament of Matrimony?
A. The chief ends of the Sacrament of matrimony are:
(1) To enable the husband and wife to aid each other in securing the salvation of their souls;
(2) To propagate or keep up the existence of the human race by bringing children into the world to serve God;
(3) To prevent sins against the holy virtue of purity by faithfully obeying the laws of the marriage state.
-Baltimore Catechism, No. 3
I hope that you weren't deliberately causing confusion regarding the purpose of marriage when you posted this excerpt from the Baltimore catechism in this way. It has been dogmatically stated by the magisterium many times that the primary purpose of marriage is the procreation and education of children. All other purposes must be subordinated to the primary purpose. Here is what Pope Pius XII said about it:
Now, the truth is that matrimony, as an institution of nature, in virtue of the Creator's will, has not as a primary and intimate end the personal perfection of the married couple but the procreation and upbringing of a new life. The other ends, inasmuch as they are intended by nature, are not equally primary, much less superior to the primary end, but are essentially subordinated to it. This is true of every marriage, even if no offspring result, just as of every eye it can be said that it is destined and formed to see, even if, in abnormal cases arising from special internal or external conditions, it will never be possible to achieve visual perception.Like the language used by Pope Pius XI in Casti Connubii, this language of Pope Pius XII could be seen as invoking infallibility, since he calls upon the witness of every source of Catholic theology and states that he wishes to make a definitive declaration that puts a stop to all deviant opinions. All other purposes of marriage must remain subordinated to the primary purpose which is the procreation and education of children.It was precisely to end the uncertainties and deviations which threatened to diffuse errors regarding the scale of values of the purposes of matrimony and of their reciprocal relations, that a few years ago (March 10, 1944), We Ourselves drew up a declaration on the order of those ends, pointing out what the very internal structure of the natural disposition reveals. We showed what has been handed down by Christian tradition, what the Supreme Pontiffs have repeatedly taught, and what was then in due measure promulgated by the Code of Canon Law. Not long afterwards, to correct opposing opinions, the Holy See, by a public decree, proclaimed that it could not admit the opinion of some recent authors who denied that the primary end of marriage is the procreation and education of the offspring, or teach that the secondary ends are not essentially subordinated to the primary end, but are on an equal footing and independent of it.