280 THE DEVELOPMENT OF LEGAL REASONING

agreed that he had no traditional authority for this doctrine¹—in other words, the implications of the Koranic passage began to be considered in the time of 'Aṭā'.

Technically more polished are the opinions that the mukātab becomes free as soon as he has paid off his value—this seems to have been the current doctrine of the Kufian school at one time;² or that he becomes free pro rata of his payments—this seems to have been connected with the Iraqian opposition;³ or that he becomes free immediately, and the payments due from him are ordinary debts.⁴

Finally, the systematically most consistent doctrine that the mukātab remained a slave as long as part of the stipulated sum was still unpaid, prevailed in Iraq and in Medina where it was projected back to Zaid b. Thābit,⁵ to Ibn 'Umar,⁶ and finally to the Prophet himself.⁷ All this ante-dated documentation is later than the simple reference to the ancient Medinese authorities 'Urwa b. Zubair and Sulaimān b. Yasār, a reference which itself dates only from the first half of the second century A.H.⁸

Even after the final doctrine on the mukātab had prevailed, some concessions—presupposing it—in favour of a defaulting mukātab were made; but they were subsequently reduced, though not completely eliminated, in the interest of stricter systematic consistency. We have discussed elsewhere⁹ one of these concessions which was put into the mouth of 'Ali and acknowledged by Ibn Abī Lailā and, to a lesser degree, by Abū Hanīfa and Abū Yūsuf, but rejected by Shāfi'ī. On the