A Word to Non-Catholic Respondents about the Tribunal
The Catholic Church presumes that every marriage – whether it involves a Catholic or not – is valid until the contrary is proven. This presumption is unaffected by the granting of a civil divorce.
This presumption of validity can be challenged before a Church Tribunal by one of the parties in the marriage. The burden of proof, however, rests on the person who makes this petition, and the Tribunal itself can only declare whether or not it has been proven that the marriage was invalid from the start. It has no power to make the marriage null or invalid.
A previously married non-Catholic who wishes to marry a Catholic has a legitimate interest in asking a Church Tribunal to examine the question of the validity of his or her marriage. In such a case the Tribunal of the Catholic Church would make a judgment about the alleged nullity of the marriage of two non-Catholics solely in order to determine whether the Catholic can marry the non-Catholic. If indeed the non-Catholic is bound by a previous valid marriage, the Catholic Church, which does not recognize divorce, cannot permit the Catholic party to marry this person.
A non-Catholic party in such a case, whether the petitioner or the respondent, has the same rights as a Catholic before the Tribunal.
The rights include the right to be heard, to offer arguments and proofs, as well as to know and be able to respond to the arguments and proofs presented by the other party. Each party has the right to choose an advocate (who has to be approved by the Tribunal) to assist him or her in exercising those rights before the Tribunal.
It is the task of the Tribunal to make its decision in light of the arguments and proofs presented by both sides and the principles of sound judgment.
In judging the validity of the marriage of two non-Catholics, a Church Tribunal does not apply those positive laws of the Catholic Church which affect only marriages involving a Catholic, but only those principles arising from the natural law or divine positive law which affect the validity of any marriage.
In particular, the Catholic Church holds that certain elements belong to the very nature or essence of marriage itself as determined by the Creator and are not optional elements that can be included or excluded at will. Consequently their positive exclusion from marriage consent would make that consent invalid.
[Taken from Roman Replies and CLSA Advisory Opinions 1997, pp. 25-26.]







