Regarding the intrinsic juridical nature of Holy Matrimony, in the beautiful speech of the Holy Father to the auditors of the Roman Rota (text in Italian).
The entire attitude of the Church and of the faithful in the field of family [affairs] must be based on this truth about marriage and its intrisic juridical dimension. Nonetheless, as I recalled previously, the relativist mentality, in a more or less open or subtle way, may insinuate itself even within the ecclesial community. You are well aware of the currentness of this risk, which manifests itself at times in a distorted interpretation of the canonical norms in force.
It is necessary to react to this trend with courage and confidence, constantly applying the hermeneutics of renewal in continuity and not letting oneself to be attracted by interpretive ways which imply a rupture with the Tradition of the Church. These ways move away from the true essence of matrimony as well as from its intrinsic juridical dimension and, under various more or less attractive names, seek to dissimulate a forgery of conjugal reality.