Carool Kersten's book presents the contested ideas and values found in the writings of Muslim intellectuals in Indonesia. It is a contemporary intellectual history of Islam in Indonesia and a history of ideas, and focuses on the post-New Order Reformation period, which started in 1998. It details the debates and arguments within Indonesian Islam, the theological, social and political contexts of the arguments, and provides genealogies of the various strands of thought and their contenders. The book takes the Majelis Ulema Indonesia (MUI)’s 2005 fatwa, which condemned ‘secularism, pluralism and liberalism’, as a focus to show not only the ideas and arguments of the main camps involved in the debates, but also the diversity and transformation of thought among Indonesisan Muslim scholars, and their intellectual genealogies. Islam in Indonesia is a continuation of the author's Cosmopolitans and heretics: New Muslim intellectuals and the study of Islam, which focused on the late Nurcholish Madjid, whose intellectual legacy has influenced both progressives and reactionaries.

With the recent rise of conservatism in Indonesian Islam resulting in antagonism and polarisation, this intellectual history provides helpful insights for analysing sociopolitical-religious phenomena such as the ‘212’ (2 December 2016) rally. This rally — claimed to have drawn seven million participants — was against the Christian governor of Jakarta (Basuki Tjahaja Purnama or Ahok), demanding that he be jailed due to an accusation of blasphemy in the wake of the politicisation of local elections. Applying Kersten's intellectual history, this 212 movement is seen to reveal the sharp polarisation between progressive and reactionary Muslim intellectuals in defining non-Muslim leadership and the position of Islam, and shows the huge sociopolitical pressures that have been applied against the progressive camp through the use of theological arguments. Despite the picture of politicisation of religion, what is notable here is the growing alliance of reactionary Muslims and anti-government parties seeking a path to power. While the anti-Ahok rally may have been part of a ‘conservative turn’ in Indonesian Islam, it does not signify the triumph of the conservative camp in intellectual debates. Yet, a combination of social media, the pragmatism of political parties, and regional elections transformed MUI's accusation of religious blasphemy into a national issue. In this case, Kersten's mapping of Muslim intellectual camps into progressives, conservatives and reactionists, or substantivists versus formalists, fits well.

Kersten organises his book into six chapters, excluding an introduction and a conclusion. The first chapter provides the background for the emergence of twenty-first century intellectuals of Indonesian Islam, for whom discourses on secularism, pluralism and liberalism became a focus. He shows that such intellectual discourses did not necessarily come from purely intellectual enquiry, but have been influenced by the sociopolitical situation. The second chapter maps Muslim intellectualism in the post-New Order period, from profiling leaders (such as Nurcholish Madjid and Abdurrahman Wahid), to schools (such as Ciputat and Yogya), to camps of new ulama, organisations (Jaringan Islam Liberal, Nahdlatul Ulama's youth wing GP Ansor, and Muhammadiyah), and the individual antagonists and their organisations. It also reveals a group of new, progressive Muslim intellectuals of the twenty-first century, who are ‘not traditionalist or modernists, neither secular nor Islamist’ (p. 81).

Influenced by sociopolitical changes since the Reformation, the next chapter provides ‘adaptations, critiques and transformation’ of Islamic discourse, drawing theories from both ‘the west’ and ‘the east’. Chapter 4 discusses the relationship between Islam, statehood and democracy. It examines the place of Islam in the state by using the notions of secularism, pluralism and liberalism. This stage shows the triumph of the state ideology Pancasila in becoming a front ‘to shield Indonesia from “creeping Talibanisation”’ (p. 175) and the triumph of the Madinah Charter rather than the Jakarta Charter. Following the failure of political Islam, chapter 5 examines two types of movements influencing Islamisation, namely the legal formalists versus the substantivists. Chapter 6 discusses the debate on notions of religious pluralism, human rights, and freedom of thought between the progressive and reactionary camps.

The book is remarkable as to its detail in pointing out almost all the names of progressive and reactionary Muslim intellectuals and groups who have contributed to the debates up to 2014. The author's knowledge of, and proficiency in, Arabic and Islamic traditional thought is of clear benefit in providing analytic depth. The book concludes that the intellectual contestation shows ‘how Indonesian Muslims value state governance, civil society, and individual liberty and freedom. Whichever way they choose to go, it will be yet another instance of how religion … remains intricately entwined with social transformation’ (p. 288). Kersten shows here that among the main factors in the growing spirit of conservatism is the failure of the central government to take a clear stance on various aspects of intolerance in the Islamisation agenda. But above all, the ongoing contestations also reveal the strength of civil society in Indonesia.

The importance of this book is in helping readers to understand the atmosphere of political turbulence caused by different notions of the position of Islam and the state. Such contestations have happened and will continue to take place in the future. That being the case, and because of the material that Kersten has marshalled together, Islam in Indonesia: The contest for society, ideas and values is a must-read for researchers working on Indonesia and the intellectual history of Islam, in that country, elsewhere in Southeast Asia, and globally.