Obviously such action as might be undertaken by such a group must come after the political fact, and because of the nature of the institution the time-lapse between deed and decision might be generations. The business of discovering the law is at times very much like legislation, but the non-officialised body of the ‘ulama’ tend to convert their function to that of a huge, unwieldy board of judicial review. However, since there is no priesthood in Islam, the ‘ulama’ form an undefined and unwieldy body. The Sunni ‘ulma’ are distinguished from others by their acknowledgement of the “canonical” sources of the Shari‘ah. Learning, or ‘ilm, is necessary for the discovery of what the Shari‘ah is, and this qualification is the source of the title ‘ulama’. The immediate source of authority is somewhat more difficult to ascertain. Thus, the proximate sources of authority are the Qur’an, the Sunnah, Ijma‘ and qiyas. The successors of Mohammad may only know the Shari‘ah by reference to the Qur’an, to the behaviour of Mohammad, and, wherever these sources are not explicit, to the consensus of Muslims – or indeed by reference to analogical judgment. The principal difference between the Sunni and later Shi‘ite persuasions is the Sunni doctrine that the last and definitive revelation is the Qur’an, and Mohammad is the last human being to be endorsed with revealed knowledge of right and wrong. It is only the good that God commands and only the evil that He forbids. The pre-requisite for obedience is belief. The pre-requisite for the knowledge of the Shari‘ah is acknowledgement of the established sources of the Shari‘ah, i.e. Human beings may not change the laws laid down by the Shari‘ah but they my know them or not know them, interpret them or not interpret them, obey them or disobey them. It is elastic only in the sense that some parts of one of its sources (the Qur’an) are given in such general terms as are capable of different interpretations at different times, and the validity of some parts of another source (Hadith) depends upon historical authenticity. It is claimed that the Islamic law is laid down for all times to come. from prophet to prophet, but the Shari‘ah of a prophet is the best law for the time for which it is laid down. Theoretically, the Shari‘ah is changeable from time to time, i.e.
As a body of more or less concrete law, the Shari‘ah itself must be authorized from some source, which is presumably qualified to judge right from wrong.
In the legalistic theory of the caliphate expounded by the Sunni jurists the Shari‘ah is quite obviously the source of all authority, including political authority as well. The structures of political authority in Islam are by no means as simple as it seems at first glance.