In the canon law of the Catholic Church, a distinction is made between the internal forum, where an act of governance is made without publicity, and the external forum, where the act is public and verifiable. In canon law, internal forum, the realm of conscience, is contrasted with the external or outward forum; thus, a marriage might be null and void in the internal forum, but binding outwardly, i.e., in the external forum, for want of judicial proof to the contrary. Etymology The judicial jurisdiction of the Catholic Church is expressed by the word Forum, the Latin designation for a place containing a tribunal of justice. Theoretical basis As the Church is a perfect society, she possesses within herself all the powers necessary to direct her members to the end for which she was instituted and she has a correlative right to be obeyed by those subject to her. This right is called jurisdiction, and it is the source of all the Church's action that is not derived from the power of Sacred orders. It is this jurisdiction which is the foundation of ecclesiastical law, both externally and internally binding, and from Apostolic times it has been put into practice by the Church's rulers.Just as the civil State has the legitimate jurisdiction over its subjects to guide them to the end for which it is instituted, because it is a perfect society, so likewise the Church, being constituted by Christ as a perfect society, possesses within itself all the powers necessary for lawfully and effectively attaining the end for which it was established. Internal forum vs. external forum As the power of the Church extends not only to its individual members but also to the whole corporate body, not only to questions concerning the conscience but also to the public actions of its subjects, ecclesiastical jurisdiction is distinguished into that of the internal and external forum. It may so chance that circumstances may bring about a conflict between the internal and external forum. Thus, for example, a marriage may be null and void in the forum of conscience, but binding in the external forum for want of judicial proofs to the contrary, and vice versa. Internal forum The jurisdiction of the internal forum deals with questions concerning the welfare of individual Christians and with their relation to God. Hence it is called the forum of conscience (Forum conscientiae). It is