This verb refers to judicial decision-making after investigation—literally 'to know thoroughly' in order to render judgment. Both occurrences are in Acts, involving legal proceedings. The Jewish leaders ask the Roman commander to bring Paul down so they can 'determine' his case more accurately (Acts 23:15), and Felix later postpones Paul's hearing, saying he will 'decide' the matter when the tribune arrives (24:22). The term implies not arbitrary decision but careful investigation leading to authoritative determination. The judicial context is clear from the German 'to know through' and French 'discerner,' emphasizing the investigative aspect before verdict.