JUDEX NON POTEST ESSE TESTIS IN PROPIRA CAUSA by Law Professor Latin, meaning A judge cannot be witness in his own cause. Related Posts:TESTISNEMO DEBET ESSE JUDEX IN PROPRIA CAUSAALIQUID POSSESSIONS ET NIHIL JURISJUDEXJUDEX NON POTEST INJURIAM SIBI DATAM PUNIREUBI NON EST PRINCIPALIS NON POTEST ESSE ACCESSORIUS