For Augustine, evil is simply non-existence, ‘the loss of good’, since God and no other has given everything existence; all sin is a deliberate falling away from God towards nothingness, though to understand why this should happen is ‘like trying to see darkness or hear silence’.38 It was understandable that the ex-Manichee should thus distance himself from the notion previously at the centre of his belief, that evil was a positive force constantly struggling for mastery with the force of light, but as a definition of evil it has often been criticized.