This book does not concern, as the title appears to indicate, the nature of dissent in Muslim societies. Rather, it is an uneven account of the doctrines and historical development of Ibāḍism and a cursory study of the development of Islamic law and its relationship to political authority. The author labels all forms of radical dissent “Ibāḍism” (10), on the one hand distinguishing this term from the actual sect called by that name, but on the other discussing the development of that sect. The equation of violent rebellion with Ibāḍism is misinformed, and the cover image of a modern black-masked militant holding an assault rifle, which bears no relationship to Ibāḍism, compounds the error. Although classical Ibāḍism mandates rebellion against unjust rulers whenever possible, it was never violent in the manner of contemporary Islamist militants and is generally seen as one of the qaʿada (quietist) branches of Khārijism. Only at the end of the book is it apparent that the author is building an argument for the malleability of religious doctrine, as he contrasts contemporary Ibāḍism, especially in Oman, with what he sees as an early history of Ibāḍī rebellion. The author knows that Ibāḍīs often lived peacefully under non-Ibāḍī rulers, but this is mentioned as an insignificant detail in a narrative that focuses on rebellion in early Islam.

The author performs a genuine service to scholarship by translating selections from two Ibāḍī legal texts, the ninth-century Mudawwana by Abū Bashīr b. Ghānim al-Khurāsānī, and the tenth-century Jāmiʿ of Ibn Baraka of Oman. The selections from the Mudawwana concern miscellaneous topics that are not clearly relevant to the theme of the book. The selections from Ibn Baraka concern jihad, but the lack of comparison on this topic with other schools of Islamic law can mislead a reader into thinking that, for example, only Ibāḍīs reject killing an enemy with fire, whereas this opinion is commonly accepted across legal schools. The author says he wants the texts to speak for themselves

Some of the book's statements about the state of Islamic studies are inaccurate: he says, “Islamicists often use the word ‘codified’ in relation to Islamic law” (134), but scholars have long recognized that the Shariʿa is a discussion of Muslim duties and ethics, not a code of law; he says that Islamicists specializing in Islamic law are trained legal professionals without training in classical Islamic law (134), but such people would not be called Islamicists at all. He alleges that, by its very nature, modern scholarship encourages a reductionism that allows the oversimplification of concepts and historical realities (18), but sound scholarship does the opposite. The correctives he offers on the genesis of Islamic law (e.g., the posthumous authority granted to the eponymous founders of the legal schools) are not new to Islamicists.

Souaiaia discusses the development of ʿazzāba councils in North Africa to replace the function of the Imām and the mainstreaming of Ibāḍism in the Sultanate of Oman. He states that the ʿazzāba councils were dissolved nearly a century ago, but in fact the ʿazzāba in the Mzāb continues to flourish. The information on Oman is based on his observation of “religious events, marriage ceremonies, and educational sessions performed in private and public spaces” (154). He describes modern Oman as “a deeply intriguing example of a nation that has preserved its traditional heritage while embracing many of the practices of modern, pluralistic societies” (154), which would ring true for many who know contemporary Oman. More controversially, he concludes that social protocols are determined by one's stage in the life cycle rather than tribe, family, or ethnicity (156). He admires the Grand Mufti's “candid, unrestrained, and refreshingly original” views on public affairs (159) and the Omani government's ability to manage dissent “instead of suffocating it in the interest of preserving consensus” (158), a contention that would be disputed by Khalid al-Azri, author of Social and Gender Inequality in Oman (Routledge, 2013). Souaiaia attributes this moderation to the differences between contemporary and classical Ibāḍism (161), whereas many Omanis (rightly or wrongly) allege that Ibāḍism itself is the source of their moderation. He seems unaware of the arrests of dissidents in Oman and wrongly maintains that the government of Oman has not co-opted the authority of the religious institutions (164). He nonetheless recognizes that in Oman, as in other Gulf states, a single family monopolizes power—circumstances, he notes ominously, that are similar to those under which the first Muslim civil wars took place. He concludes that contemporary Ibāḍism is “more mainstream than many modern Islamic movements,” and constitutes an effective tool for integrating civil social institutions with government-provided services and for empowering innovation (161). He points out the malleability of religious doctrine and states that the differences between Sunnis and Ibāḍīs today are insignificant (169).

Aside from the translation of a few legal texts, the book does not contribute to scholarship on Ibāḍism. The author seems unfamiliar with the most important recent scholarship on Ibāḍism, especially the works of John Wilkinson, whose deconstruction of early Ibāḍī history and the development of Ibāḍī law problematizes the common narrative accepted by Souaiaia. His observation that the Khawārij were not a coherent group is nothing new to scholars of early Islam, but his labeling of all who rebelled against ʿUthmān as Khawārij is anachronistic.

The intended audience of the book is unclear. The discussion on the nature of Islamic law seems to be aimed at novices, but the dry translations of legal texts are unlikely to be of interest to such readers. On the other hand, the author avoids conventions that would make the book more accessible to non-Arabists, as in the manner of citing Qurʾanic verses and the use of Gregorian dates. There are also inconsistencies in the transliteration of Arabic words. The author states that his topic and approach are controversial because his book deals with dissent, but it is the use of “Ibāḍism” as code for Islamic radicalism that will make the book controversial for academics and anathema to Ibāḍīs.