EXERCISE OF JURISDICTION

Subject matter jurisdiction is the power of a court to hear, try and decide a case. On the other hand, the exercise of jurisdiction is the court's act of actually taking cognizance of a case.

When a court has jurisdiction over the subject matter, it can validly render a judgment. The judgment may be wrong, but this does not deprive the court of jurisdiction. The erroneous judgment may be corrected on appeal.

On the other hand, when a court has no jurisdiction, any judgment that it renders will be void. So also, when a court acts with grave abuse of discretion amounting to lack or excess of jurisdiction, the judgment is void. In both instances, the proceedings may be annulled through a petition for certiorari under Rule 65.

In the case of ANSELMO ELLO VS. JUDGE OF FIRST INSTANCE OF ANTIQUE and INOCENCIO VALDEVIN, G.R. No. L-26802, July 23, 1926, the Supreme Court cited De la Cruz vs. Moir (36 Phil., 213), thus:

None of the acts set out in the petition affect the jurisdiction of the court. They are acts performed in the exercise of jurisdiction; and, even though the decision of the court upon each one of the questions presented by the allegations of the petition was wrong in fact and in law, his jurisdiction would remain unaffected. As we have said so many times, it is always necessary to bear in mind the difference between jurisdiction and the exercise of jurisdiction. When a court exercises its jurisdiction an error committed while engaged in that exercise does not deprive it of the jurisdiction which it is exercising when the error is committed. If it did, every error committed by a court would deprive it of jurisdiction and every erroneous judgment would be a void judgment. This, of course, is not possible. The administration of justice would not survive such a rule. The decision of the trial court in the case before us holding the certain ballots cast by illiterates which had been prepared for them by the inspectors of election were legal and valid although the illiterates did not, previous to the preparation of their ballots by inspectors, take the oath required by law showing that they could not cast their ballots without assistance, is a decision entirely within the jurisdiction of the court, even if we concede for the sake of argument that the court was wrong in that decision. The same could be said if he had held the precise contrary and had excluded all of the ballots cast by illiterates; and, of course, it necessarily follows that his failure to separate those which the petitioner claims were illegal from those he claims were legal does not alter the situation. The court has power and authority to conduct the case as he believes law and justice require and whatever he does is within his jurisdiction so long as he does not violate the principle of due process of law or transcend the limits of the case before him.