If you judge, understand.

Explanation

(English-origin maxim.) A judge must fully comprehend the matter before rendering judgment — understanding the facts and the law is the prerequisite of just decision.

Where this applies

• A judge rules on a complex patent case without reading any of the technical evidence, and the appellate court reverses because the judge did not understand the matter before deciding it.
• A family court judge awards custody without learning anything about either parent's living situation, and the ruling is overturned for lack of understanding.
• A magistrate sentences a defendant for violating a statute she has not actually read, and the conviction is reversed because she judged without comprehension.