Through the different cultures and for centuries, the family has been recognized as the indissoluble foundation of society, as the primary cell of the structure of peoples. The family, founded on marriage, that is, on the union of love and life between a man and a woman and their reciprocal, faithful and lasting gift of self open to life, constitutes a common good of humanity and a guarantee of its existence as a human society.

This was recognized once again during the International Year of the Family that was celebrated 10 years ago, in which the Church took part with dynamic enthusiasm.

It is therefore possible to speak of this family reality as a patrimony of humanity, the support of a healthy social fabric that permits a human development of peoples. The proclamation and defence of this truth are not merely a Christian prerogative, although the act of responding to a plan of God, after creation, enlightens, deepens and binds believers with great force.

The fact that Aristotle, three centuries before the beginning of the Christian age, emphasized the value of marriage and the family and the importance of children who renew the spouses' union and procure stability and perpetuity to their parents' union, is an element that merits special reflection (Book VIII, 14). Aristotle even reaches the point of asserting that marriage comes before and is superior to the State.

In recent years, the family institution has been relativized in different ways:  for example, through recognition of de facto unions formalized between the parties concerned with contracts that endow these unions with an alternative status to that reserved for marriage and similar social benefits.

An element common to all de facto unions is, precisely, the character of non-matrimonial unions, in other words, those founded on rejection of the commitment of marriage. We are familiar with the principle of justice recognized by every pluralistic society and by virtue of which everything that is equal must be treated equally and everything different, differently. However, this principle would be violated were we to attribute to de facto unions a juridical importance identical or similar to that which the family founded on marriage rightfully deserves.

In line with these principles, the distinction between public and private interests should be taken properly into consideration.

As regards the former, it is the duty of society and the public Authorities to protect and promote them. In the latter case, the State must limit itself to guaranteeing freedom.

Where public interests are concerned, public law is applied. Whatever regards private interests, must, on the contrary, be treated in the private sphere.

Marriage and the family, insofar as by nature they are ordered to procreation, are the irreplaceable source of civil society, they form its basic nucleus and are therefore of public interest. Two or more people can choose to live together, with or without sexual relations, but this cohabitation does not therefore constitute public interest.

The public Authorities can avoid dealing with this choice which is private in character. De facto unions are the result of private behaviour, and private they must remain.

Moreover, the forms of cohabitation that qualify to be listed among de facto unions are so varied and the situations are so different that it would seem difficult and problematical to group them all together under a single juridical regime.

Nor does it seem superfluous to add that the absence of public recognition for de facto unions does not discriminate against them in comparison with marriage. Indeed, the opposite is true; that is, that the equally public importance attributed to a de facto union and marriage constitutes a certain discrimination against the institution of marriage.

To the extent that it is a matter of de facto situations, it seems appropriate that public Authorities limit themselves rather to determining the private relations of justice, for example, concerning inheritance, that can be connected in each individual case with the birth of children, with the duration of the cohabitation, with possible professional disadvantages suffered by one of the parties in virtue of his/her dedication to their life in common.

Should disagreements arise in the application of the norms of private law, the judicial ruling seems sufficient and adequate to resolve the practical and private demands of justice that may possibly have emerged during de facto cohabitation.

With regard to single-sex de facto unions, the same observations hold true; and to these we should add the seriously contradictory nature inherent in the assimilation of such unions into marriage which, on the other hand, in international and in almost all national legislation, regulates the relationship between persons of the opposite sex.

It is also important to emphasize the educational risk connected with recognition of the right to adoption of single-sex couples. Indeed, this contradicts the commitment to always seek "the best interests of the child", considered in his ultimate dignity (Convention on the Rights of the Child). In an adoptive family, the child's right to the fundamental and irreplaceable experience of a father and a mother, as in a natural family, should be recognized.

The Holy See profoundly hopes that the CIEC will pay due attention to these observations, based on merely rational considerations, which would prevent the juridical institutions fundamental for an orderly coexistence of human society from drifting into dangerous relativism.

*L'Osservatore Romano. Weekly Edition in English n.42 p.9.