Jurisdiction is the power to declare the law; and when it ceases to exist, the only function remaining to the court is that of announcing the fact and dismissing the cause.

Explanation

(English-origin maxim.) When a court loses jurisdiction over a matter, its only remaining function is to announce that fact and dismiss the case — any order entered after jurisdiction ceases is void.

Where this applies

• A federal court discovers mid-trial that the case involves a purely state-law dispute between citizens of the same state, and the court must dismiss the case because it has no subject-matter jurisdiction — its only remaining function is to announce that fact.
• An appellate court realizes the trial court's jurisdiction expired when the parties settled the case, and any orders entered after settlement are void because the court had no remaining power to act.
• A bankruptcy court discovers that the debtor filed in the wrong district, and the court must dismiss because once jurisdiction is shown to be absent, the only thing left to do is announce the deficiency and close the case.