The 3rd/9th and 4th/10th 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 usul al-fiqh (Islamic legal theory) al-Risala by al-Shafi`i (204/819), and what is recognized as the second work al-Fusul fi-al-usul by al-Jassas (370/981). Due to the absence of a major work devoted solely to usul 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 usul 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 usul 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 usul 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 usul al-fiqh (Islamic legal theory) is in fact illusory. The years mentioned here are the death year of al-Shafi`i, the author of al-Risala, often reckoned to be the first treatise in usul al-fiqh and the death year of al-Jassas (370/981), the author al-Fusul fi-al-usul, 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 usul 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 usul al-fiqh without a strict school affiliation.

I trace the lineage of the debates found in al-Fusul fi-al-usul by al-Jassas (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, kalam, hadith, and tafsir, which contain scattered information relevant to the study of usul 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 usul to usul 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-Jassas's al-Fusul. The subsequent three chapters examine the discussions of the period over the use of khabar al-wahid (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 usul al-fiqh in the period between al-Shafi`i and al-Jassas that contradict commonly held opinions. It will therefore be of interest to scholars researching the early history of Islamic law and legal theory, but also to the broader audience who are interested in the authority problem in Islam and the discussions related to orthodoxy and orthopraxy.

If you made up your mind that the Islamic rituals are inextricably linked to bodily movements and physical space, this thesis aims to challenge and persuade you otherwise. It is conceivable that one may perceive Islamic rituals devoid of corporeal actions or spatial attributes as a relatively recent innovation introduced by contemporary Muslim intellectuals, possibly catalyzed by the exigencies imposed by the Covid-19 pandemic. This study, however, will astound you by providing evidence that this idea of distant rituals can be traced back to the 9th century, when early Muslim jurists conceptualized several Islamic rituals without reliance on physicality or spatiality, such as the "Heart Prayer" and "Ship Prayer". Moreover, this study offers a comprehensive reassessment of the historical evolution of religious rituals’ performance and explores their long-held perception of being unaltered. By drawing upon legal and philosophical evidence, this research presents a historical context that supports these reinterpretations. A significant aspect of this evolution is the emergence of cyber-Islamic rituals, which has profound implications for both individuals and communities at large. This dissertation goes beyond theoretical examination and delves deeper into the nuanced implications of online Islamic rituals, specifically those pertaining to religious authority, authenticity, and identity formation. By presenting empirically grounded case studies encompassing diverse Sunni and Sufi communities situated in both Egypt and the United States, this study augments its findings with real-world instances, thus enriching the scholarly discourse on this subject matter.

Is human action the result of metaphysical or blind, undirected natural causes, or is it the product of purposeful choices made by the human agent? I aim to answer this question by exploring how a medieval scholar, an 8th/14th century Māturīdī-Ḥanafī jurist known as Ṣadr al-Sharī‘a (d. 747/1346), reasoned about and proved human free agency as the basis of normative responsibility. In this study, I delve into the transformation of meta-ethical discourse in usul al-fiqh concerning the problem of free will, tracing its historical developments. Based on this historical analysis, I focus on the gamechangers, Rāzī, and Ṣadr al-Sharī‘a, and explore their contrasting theories on human agency using textual analysis method. Then, I provide a comparative analysis between their theory of agency and relevant contemporary theories, subjecting them to a dialectical confrontation with their opponents. Ultimately, I argue that Ṣadr al-Sharī‘a’s theory of agency offers a compelling argument for free will in our contemporary context.