Nature of the Tribunal
The Council of Trent during Sessio XXIV, ordered that matrimonial and criminal cases be examined and tried by the bishop of the diocese concerned. The 1917 Code of Canon Law [CIC/17] regulated the judiciary department of the diocesan curia in such a way that the bishop, the ex-officio judge (iudex natus) of first instance, would have a Judicial Vicar or Officialis, possibly associate judicial vicars or vice-officialis, synodal judges, a sole-judge or collegiate tribunal auditors, relators, assessors, as well as a representative. There is always a bid difference between the First Instance Tribunal and other Instances. Although there are elements common to all of them, the First Instance is distinguished by the fact that: (a) it sets the limits of the controversy, (b) receives the material for establishing the facts, (c) admits the main exceptions.
 
It is the Judge who is entrusted with the noblest function of judging (jus dicere) in a lawsuit by applying to a specific case the Law issued in the Legislator. The Judge, whose task it is to see that justice is carried out, is faced with two situations in the course of the process: that of the fact which requires the objective truth, and that of law which claims fidelity to the norm. The firm adhesion to one and to the other reality is what produces the beautiful fruit of justice. The judge and the parties concerned must exert the appropriate attention and interest in order for the process, once begun, to attain its proper and logical end.
 
The initiative of the parties is called the instance of the parties to the action, and that of the judge, official expediting. Expediting a court action means taking the action necessary to avoid delays resulting from negligence of either the parties or the judge, to ensure that the process develops lawfully, and a final decision is reached in due time. In canonical procedural law, although there are no specific norms to control the actions of the judge, there is a general guiding principle and different provisions which define explicitly and implicitly the judge’s procedural activity.
(c. 1452)
 
The judge would be exceeding his jurisdiction if he acts without the Petition of the plaintiff, nemo judex sine actore, or if he resolves a controversy beyond what is requested by the party in the petition, sententia debet esse conformis libello, ne eat iudex ultra petita partium. He exceeds his authority if he decides in favour of or against persons other than the plaintiff or the respondent; if he grants or refuses anything other than that which is requested by changing the petitum or the causa petendi; if in judging, he adheres to facts other than those alleged and proved: iudex iudicare debet iuxta allegata et probata; quod non est in actis non est in mundo. A judge does not exceed his duty, however, if he determines and declares the juridical norms applicable to the facts alleged and proved: iura novit Curia; narra mihi factum, dabo tibi ius.
 
A Tribunal is composed of a group of persons each with his or her own respective functions. The Judges are members of that group. In the Code of Canon Law in the book on procedural law, the word “Tribunal” is used at times to refer to the entire court (c. 1423) while at other times to the collegiate group of judges (cc. 1425; 1427). In the strict sense, the word “Judge” signifies a person who is legitimately constituted with the ecclesiastical jurisdiction to hear and resolve contentious or criminal cases that are within the competence of the Church, according to the prescriptions of the law.
 
Cfr. Code of Canon Law Annotated, 2nd edition revised and updated of the 6th Spanish Language edition, 2004,
edited by Ernest Caparros - Michel Thériault - Jean Thorn, pp. 1102-1103.