Pius XI – A Great Pope of Immortal Memory – presents the infallible dogma of the Church that marriage, whether sacramental or merely natural, is a divine institution in his masterful Casti connubii:
“5. And to begin with that same Encyclical [i.e., Arcanum, of the Great Pope Leo XIII], which is wholly concerned in vindicating the divine institution of matrimony, its sacramental dignity, and its perpetual stability, let it be repeated as an immutable and inviolable fundamental doctrine that matrimony was not instituted or restored by man but by God; not by man were the laws made to strengthen and confirm and elevate it but by God, the Author of nature, and by Christ Our Lord by Whom nature was redeemed…”
The result? No merely human authority – not even the state – has any legislative or judicial authority whatsoever over the bond of marriage! Period. Thus states the Pontiff:
“and hence these laws cannot be subject to any human decrees or to any contrary pact even of the spouses themselves. This is the doctrine of Holy Scripture; this is the constant tradition of the Universal Church; this the solemn definition of the sacred Council of Trent, which declares and establishes from the words of Holy Writ itself that God is the Author of the perpetual stability of the marriage bond, its unity and its firmness.”
Nor are the spouses themselves free to construe the bond as they will. Their freedom concerns their entry or non-entry into this covenant. Once they enter it, they have no freedom whatsoever to break it or manipulate it. Their freedom within the horizon of the bond is to grow in love, to give themselves to each other, to actualize (by God’s grace) a unique societal unity that can never be repeated. Each marriage is a world of beauty if lived well. The pope:
This freedom, however, regards only the question whether the contracting parties really wish to enter upon matrimony or to marry this particular person; but the nature of matrimony is entirely independent of the free will of man, so that if one has once contracted matrimony he is thereby subject to its divinely made laws and its essential properties (art. 6).
That the state has no authority over the bond does not, however, prevent the state from forbidding false notions of the bond, those that contravene either nature itself or also the divine positive law of the King of the Universe, Jesus Christ:
8. From this it is clear that legitimately constituted authority has the right and therefore the duty to restrict, to prevent, and to punish those base unions which are opposed to reason and to nature….
Catholics distinguish sacramental marriage – any valid marriage between validly baptized Christians – and natural marriage: any valid marriage between partners at least one of whom is not baptized. (There is no possibility of a merely natural marriage for partners both of whom are baptized. A marriage between the baptized is either valid or invalid. If valid, it is sacramental.) This distinction involves a hierarchy. The natural marriage is, while intrinsically indissoluble, extrinsically dissoluble. That is, by divine appointment, an authority can be given the power to dissolve it. We say “extrinsic” because no couple has authority to break its own bond (i.e. every bond is “intrinsically [by the partners] indissoluble”).
But only divine appointment allows for the dissolution of a consummated merely natural marriage. Moses and the Old Testament priests served that function when the covenant functioned before Christ. Now that the covenant functions only in the Catholic Church, the keeper of the One True Religion, it is only the Catholic Church that has any authority over the dissolution of a natural bond. Pius XI:
35. And if this stability seems to be open to exception, however rare the exception may be, as in the case of certain natural marriages between unbelievers, or amongst Christians in the case of those marriages which though valid have not been consummated, that exception does not depend on the will of men nor on that of any merely human power, but on divine law, of which the only guardian and interpreter is the Church of Christ.
But this authority, the Catholic Church, has absolute no power to break a consummated sacramental bond. She is not God but his servant!:
However, not even this power can ever affect for any cause whatsoever a Christian marriage which is valid and has been consummated, for as it is plain that here the marriage contract has its full completion, so, by the will of God, there is also the greatest firmness and indissolubility which may not be destroyed by any human authority (art. 35).
The upshot of the infallible Catholic teaching on marriage: No other union than that of one man and one woman, for life!, is a marriage. All other so-called unions are shams. No laws but God’s laws are valid concerning the bond. And no laws attempting to create a new bond have any validity of law whatsoever. Instead, all laws that contravene the divine institution are the hot air of deluded minds. God help us all.