My paper will explore boundaries and rights, the public and the private, as to the enforcement of religious legal rules in societies self-consciously founded on Islamic law. I employ as my case-study legal and social controversies aroused by the Saudi Hay’at al-amr bi-al-ma`ruf wa-al-nahy `an al-munkar, the government agency charged with “ordering the good and forbidding the evil.” The paper will first lay out some of the laws fixing the powers of the Hay’at, including various statutes issued by the king (...) but, of equal or greater importance, the received medieval fiqh rules governing the muhtasib . Focus shall be on an issue much debated in the classical law and also a long-time bone of contention in Saudi society, namely the legal limits on the powers of the Hay’at to investigate and punish immoral acts occurring in private. Limits on such powers stem from two sources, both in the law and in social understandings of that law. One source, the more prominent in public debate, concerns revelatory and fiqh and related social norms against spying or prying into people’s behavior and against undue attempts to expose people’s sins. Notably, however, this restriction affects only enforcement. The pervasiveness of laws considered to arise from the relationship of the individual to God still stands. A solitary immoral act performed in privacy can still be a sin and a crime, and punishable if it is somehow legitimately known and proved . The second source of restrictions is more far-reaching, going beyond issues of investigation and proof. As held by the majority of scholars, the Hay’at may not compel or forbid any actions for which the religious-legal ruling is under classical law a matter of legitimate difference of scholarly opinion; or inversely, the Hay’at may compel or forbid only those actions as to which there is a divine command known to a certainty either from a revealed text or from the consensus of scholars. A commonly noted abuse by the Hay’at in Saudi Arabia has been to attempt to enforce rules lacking requisite certainty, such as requiring veiling of the face. Rules known to a certainty have a pervasive role in Islamic constitutional theory. In principle, such rules must be enforced, regardless of whether they concern matters other societies may consider individual or private, such as changing one’s religion. Rules lacking that high degree of certainty cannot – without separate justification on grounds other than religious text – define sins or crimes or be enforced as general rules by the state. Though seemingly scholastic and philosophical, this restriction is potentially crucial in defining a realm of individual autonomy in religious matters and shaping the boundary between public and private in societies self-consciously founded in Islamic law. It is important to examine to what extent the restriction is reflected in legal and social practice in such societies. (shrink)