Antrieb [m] (der ~), Beweggrund [m] (der ~), Grund [m] (der ~), Motiv [o] (das ~) {zn.} reason
motive
theme
ground
angle
motivation
motif
Was ist sein Motiv Mord zu begehen?
What's his motive for committing murder?
Was war sein Motiv, das Haus in Brand zu setzen?
What was his motive for setting the house on fire?