The Catholic Church procedural system adheres to the system of multiple instances, commonly admitted today as well in the procedure of secular law. To refer to a second instance and to second instance tribunals implies recognizing the possibility that the cases already judged by first instance tribunals might proceed to those of a higher degree in order that the alleged facts, the evidence, and the juridical norms applicable to the case might be examined ex novo integro. The tribunal of the second instance maintains the same direct and immediate contact regarding the matter submitted for trial as the first degree tribunal, adding to the acts what has been done, in the words of the aphorism, nondum deducta deducam et noindum probata probabo.
The advantage of a potential second instance is that it provides a greater guarantee that justice will be administered with rectitude under different aspects: 1) the correction of errors and the revision of unjust sentences; 2) the benefitof having a controversial matter submitted to different judges; 3) the greater authority given to judges of a higherdegree.
A case heard in a tribunal of the second instance preserves its own identity, and only the judgement given by the superior tribunal is decisive and effective.
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. 1122-1123.