The Code of Canon Law's norm concerning mental incapacity was further enriched, he noted, by the Instruction 'Dignitas connubii' of January 25, 2005.
Benedict XVI explained that certifying that a mental incapacity existed must meet specific conditions: "there must be a specific mental anomaly that seriously disturbs the use of reason at the time of the celebration of the marriage, ... or that puts the contracting party not only under a serious difficulty but even under the impossibility of sustaining the actions inherent in the obligations of marriage."
The Church must not fall into a pessimistic view of marriage that "considers marriage as almost impossible," the Holy Father warned.
"Reaffirming the inborn human capacity for marriage is, in fact, the starting point for helping couples discover the natural reality of marriage and the importance it has for salvation. What is actually at stake is the truth about marriage and about its intrinsic juridical nature, which is an indispensable premise if people are to understand and evaluate the capacity required to get married," the Pope said.
"Such capacity," he explained, "must be associated with the essential significance of marriage - 'the intimate partnership of married life and love established by the Creator and qualified by His laws' - and, particularly, with the essential obligations inherent to marriage that must assumed by the couple."
Finally, Pope Benedict cautioned the jurists about "certain 'humanistic' schools of anthropology, which tend towards self-realization and egocentric self- transcendence." These schools "idealize human beings and marriage to such an extent that they end up denying the mental capacity of many people, basing this on elements that do not correspond to the essential requirements of the conjugal bond."