Appeal denotes both the right to question the validity of a judicial decision and the protocols for its reversal. Scholarly consensus for much of the twentieth century held that the decision (ḥukm) of a qāḍī is final and irrevocable, that a judge may not change his mind once he has rendered his decision, and that a judgement may not be reversed under any circumstances. According to Schacht (Introduction , 189; cf. Tyan), for example, "[T]here is no means of reversing an unjust judgement, because strict Islamic law does not recognise