The objective nullity of some putative marriages is a reality. You can’t marry your sister. You can’t kidnap a woman and force her to wed. You can’t marry under a false pretext – e.g., pretending to be single when you’re married to someone else. You need to be sober when saying your vows. Etc.
Nevertheless, annulments should be difficult, time-consuming, and expensive to obtain.
A healthy culture of marriage demands that Church and State assume the validity of all publicly celebrated marriages. That is the wisdom behind the “presumption of validity” that the Church has always maintained toward every civil marriage, even marriages that are purely natural and non-sacramental. A culture of marriage, protected by marital indissolubility and the presumption of validity, is necessary for the protection of children, the most innocent and helpless among us. The procreation and education of children is the primary purpose of marriage. That is to say: it is greater than the secondary purpose of marriage, which is the union and mutual help of the spouses. Therefore, it makes sense that the Church and human society arrange things in such a way that protects children from parental abandonment and the burden of illegitimacy.
All marriages are subject to difficulties, conflicts, trials, and crises of various kinds. That’s why the vows say “for better, for worse, for richer, for poorer, in sickness and in health, until death do us part”. Everything is covered, even the very worst. A valid sacramental marriage cannot be dissolved for any reason whatsoever, no matter what the future may hold. It is absolutely essential, psychologically, that divorce and/or annulment never be considered an option in the minds of married people. When you say the vows, you accept every possible danger the future may bring – period.
Why is this so important? Because for most people, the married state is their means of salvation. The salvation of souls depends upon spouses enduring and persevering through the trials and tribulations of marriage. The Christian experience proves that marriages can survive their difficulties if spouses will only persevere in charity. But if one or both spouses has one eye on the annulment door, there is little incentive to persevere. It is just too easy to throw in the towel, and many do. The new “presumption of invalidity” for troubled marriages – reigning now for 40+ years and brought to a climax by the devastating motu proprio of Pope Francis – has become a classic “self-fulfilling prophecy”, achieving that which it assumes.
If the Church has failed to catechize marriage properly, the response should be a restoration of orthodox catechesis, not the normalization of of fast, cheap, drive-through annulments. In the eyes of the faithful, let the presumption of marital validity stand. Unfortunately there can be no presumption of validity for contemporary annulments.