47. The truth is that matrimony as a natural institution, by virtue of the will of the Creator, does not have as its primary, intimate end the personal improvement of the couples concerned but the procreation and the education of new life. The other ends though also connected with nature are not in the same rank as the first, still less are they superior to it. They are subordinated to it. This holds true for every marriage, even if it bear no fruit, just as it can be said that every eye is made for seeing although in certain abnormal cases, because of special internal and external conditions, it will never be able to see.
The Primary Purpose of Marriage
48. Some years ago (10 March 1944) with the precise aim of putting an end to all these uncertainties and errors that threatened to spread mistakes about matrimony and the mutual relation of its ends, We Ourselves made a statement on the order of these ends. We indicated what the inner structure of the natural disposition reveals, what is the heritage of Christian tradition, what the Sovereign Pontiffs have frequently taught, and what is established in proper form by the Code of Canon Law (Canon 1013 para I). A few years later, to correct conflicting opinions, the Holy See issued a public decree stating that the opinion of certain recent authors could not be admitted, authors who denied that the primary end of matrimony was the procreation and rearing of children or taught that the secondary ends of marriage are not subordinated to the primary end but of equal importance and independent of it ( S.C.C. Officii 1st April 1944 Acta Ap. Sedis Vol. 3, a 1944, p. 103).
49. Does this mean that we deny or diminish what there is of good and right in the personal values arising from marriage and its carrying out? Certainly not. In matrimony, for the procreation of life, the Creator has destined human beings made of flesh and blood, endowed with minds and hearts : they are called as men, not animals without reason, to be the makers of their descendants. For this end God wishes that couples be united. Holy Scripture says of God that He created man to His image and that He created the human being both male and female (Gen. I, 27) , that, as we find it so often in the sacred books, “man must abandon his father and his mother and unite himself with his wife forming one flesh” (Gen. 2, 24, Math. 19, 5, Eph. 5, 31).
Perfect Married Life
50. All this, therefore, is true and so willed by God. But it must not be divorced from the primary function of marriage, which is service for new life. Not only the common work of external life but also intellectual and spiritual endowment, even the depths of spirituality in conjugal love as such, have been put by the will of nature and the Creator at the service of our descendants. By its nature, perfect married life means also the complete dedication of the parents for the benefit of their children, and in its strength and tenderness, conjugal love is itself a postulate of the most sincere care for the offspring and the guarantee of its being carried out. (St. Thomas 3 p.q. 29 a. 2 in c. Supplmt. q. 49 a. 2 ad I).