The 3rd/9th and 4th/10 th centuries witnessed significant developments in Islamic intellectual history. Most of the hadith collections that later came to be recognized as canonical were compiled in this period and the major schools of law and certain theological schools also completed their formation during the same period. Despite this continuous progress in other fields of religious sciences, there is an unusual lapse of time between what is widely considered the first work in uṣul al-fiqh (Islamic legal theory) al-Risala by al-Sh afi'i (204/819), and what is recognized as the second work al-Fuṣul f i-al-uṣul by al-Jaṣṣāṣ (370/981). Due to the absence of a major work devoted solely to uṣul al-fiqh from this period, the majority of contemporary scholars considered it as a period of history during which there was little or no intellectual activity in the field of uṣul al-fiqh and where no significant developments took place. This assumption has driven some scholars to assign a new starting point for the field of usul al-fiqh and even different definitions of uṣul al-fiqh. The question of what in fact took place during this 'dark period,' however, has not been fully or adequately explored.

This dissertation attempts to provide an answer to this question and to shed light on the development of uṣul al-fiqh during this period. It argues that the ostensible 'gap' (or absence of scholarly production) between the years (204/819) and (370/981) in the field of us&dotbelow;ul al-fiqh (Islamic legal theory) is in fact illusory. The years mentioned here are the death year of al-Sh afi'i, the author of al-Ris ala, often reckoned to be the first treatise in us&dotbelow;ul al-fiqh and the death year of al-Jaṣṣāṣ (370/981), the author al-Fuṣul fi-al-uṣul, the next independent treatise in the field. The presence of a gap may be defended only if understood in the sense of the absence of an independent extant work in the category of us&dotbelow; ul al-fiqh. Based upon the results of this examination of extensive documentation, this dissertation argues that the 'gap' period, rather than a one in which no important developments took place, should instead be viewed by scholars as a "period of independent productivity," where the scholars of the time contributed to the topics of us&dotbelow; ul al-fiqh without a strict school affiliation.

I trace the lineage of the debates found in al-Fuṣul fi-al-uṣul by al-Jaṣṣaṣ (370/981) to earlier works and debates within the century and a half in question to earlier sources. Three sets of sources were examined in this research. The first set consists of a number of manuscripts that have either being ignored by modern scholars or been under-studied as works relevant to the history of usul al-fiqh. The second set of sources are works in various fields of the religious sciences, including but not limited to works on fiqh, kal am, hadith, and tafsir, which contain scattered information relevant to the study of uṣul al-fiqh. The third set of sources consists of citations from the scholars of the 'gap' period found in the later literature of usul al-fiqh as well as biobibliographical sources.

I have restricted the topics presented in this dissertation to the discussions of the primary sources of Islamic law due to the predominance of these issues in the documentation examined. The dissertation therefore consists of four chapters. The first chapter deals with the evolution of the concept of uṣul to uṣul al-fiqh. I examine the topics that were included within that rubric by first tracing the transformations of the term during the gap period and then by comparing al-Shafi' i's al-Risala and al-Jaṣṣaṣ's al-Fuṣul. The subsequent three chapters examine the discussions of the period over the use of khabar al-waḥid (solitary report), ijma' (consensus), and qiyas (analogy) as sources of authority for Islamic law. I chose these three issues because the legal theoretical discussions intensified around these topics during this period, and they later came to be considered among "the fundamental sources of Islamic law.".

The dissertation makes significant new claims about the early development, function, and definition of us&dotbelow;ul al-fiqh in the period between al-Shafi' i and al-Jaṣṣaṣ that contradict commonly held opinions. (Abstract shortened by UMI.).