This volume is a stimulating work on philosophy of religion from a transreligious perspective well suited for our times. The contributors have employed different – mostly outside-the-box – ideas and perspectives to look at questions about the ultimate reality from multiple locations, many of which are outside the age-old religious traditions. As the editor of the volume argues, if the goal of theology is ‘to know and articulate all we can about the divine or ultimate reality’ (1), that goal cannot be achieved by a single religious tradition's confessional theology. Since revelations and insights of one's own are not ‘adequate to the ultimate reality’ (1) and since such efforts risk ‘narrowness, distortion, and misappropriation’ (1), what we need is Theology Without Walls (hereafter, TWW). Going beyond both religious pluralism and comparative religion, the aim of TWW is ‘to understand what is truly ultimate’ (2) using ‘spiritual discernment, philosophical reflection, personal experience, and transreligious insight’ (2).

The book is a collection of non-conventional answers to the inescapable questions about ‘what is ultimate and how it is ultimate’ with respect to the ‘problematic’ aspects of life and the universe (6). Labelling traditional theological responses to these questions as walled-in-answers, the book calls for in-depth investigation of these questions and dwells upon them from outside organized religions and their theologies, which are referred to as ‘theologies with walls’. The editor claims that the approach adopted by the book is built on concepts and methods developed in the past half-century for comparison and dialogue between religions, which are conducive to theologizing across traditions. Just as the editor discredits coinages such as Christian theology, Hindu theology, Islamic theology, etc., as ‘there is just Theology, the logos of theos, of ultimacy’ (1), the contents of this book not only offer lots of scope for new thinking as regards the nature, method, purpose, and direction of inquiry into the ultimate, but also provide alternative horizons and conditions in which such an inquiry about the ultimate can take place openly, freely, inexhaustibly and provisionally, ‘without precluding surprising advances and revisions’ (1).

The book is divided into five parts. Part I, entitled ‘Why Theology Without Walls (TWW)?’, provides the rationale for the book and prepares the ground for launching its inquiry by highlighting its need and scope with the help of essays from four important thinkers in transreligious theologies. Robert Cummings Neville, one of the pioneers in this field, provides two reasons for pursuing TWW, namely, theologians’ dissatisfaction with existing theologies and the common human questions that confront them everywhere but are not answered adequately and satisfactorily by walled-in theology. Richard Oxenberg examines the reasons for theology within walls, namely, its content as a revelation of the divine in a community and its legitimacy as a continued understanding of the ultimate within a tradition. The author also applauds TWW as a new revelatory moment of the divine–human encounter that has its own soteriological power to resolve the tribalistic rivalries and chauvinistic hostilities of traditional religions, thereby offering a recognition of the divine as One. Christopher Denny compares modern humans to Sheila (a paradigmatic figure for individualized faith in Robert M. Bellah's Habits of the Heart) as they exercise human agency for their religious preferences and spiritual choices in the world of religious supermarkets in our present democratic and egalitarian era. Kurt Richardson describes the salient aspects of TWW with the help of another recently developed theological framework, namely, open field theology. While the author does not see much difference between open field theology and TWW, he strongly advocates both of them for a meaningful theological conversation about the ultimate in our contemporary times as they open up new hermeneutical space for an open-ended interaction between religions.

Part II, consisting of five essays in interreligious studies, further explores the experiences of the ultimate TWW may produce among its practitioners. Thatamanil asks us to move beyond the confines of a single religious tradition as the ultimate reality that is beyond space and time cannot be encased in one religious tradition. Nor can it comprehend the ultimate reality, which is not an ‘undifferentiated simplicity’ (60) but ‘a multiplicity’ (60). Hence, there is a need for the pursuit of interreligious wisdom as it is capable of not only unfolding ‘more than one dimension of ultimate reality’ (60) but also embodying ‘the therapeutic regimes of more than one tradition’ (58). Paul Knitter, one of the most renowned contemporary thinkers of interreligious theology, brings home to the readers his experience-based proposal of TWW. Instrumentalizing the Buddhist idea of Guru as a functional analogy, he understands Jesus’ role as a saviour in new light, namely as a spiritual benefactor, experience of whom results in salvation experience, ‘not as an atoning process that takes place outside of oneself but as a transformative unitive experience’ (67). Applying another functional analogy of liberator both to Buddha and to Jesus, Knitter discusses how Buddhists and Christians can mutually teach and enrich each other about their respective traditions’ views of liberation and social justice. Rory McEntee adopts the inter-spiritual approach of Wayne Teasdale in narrating the spiritual experiences of the Snowmass retreat-based dialogues convened by a Cistern monk Fr. Thomas Keating. The Snowmass events that brought together people of various faith traditions became a venue not only for ‘the experiences of ultimacy, especially experiences occurring within the context of long-term commitments to contemplative practice’ (86) but also for sharing ‘such experiences in collaborative ways, where the revelatory experiences of others affect our own religious quest’ (86). The author regards an inter-spiritual approach as valuable to experiencing, creating, and nurturing TWW. The essay by Weidenbaum exclusively draws upon William James's views to understand ‘different theological sensibilities’ (98) and states that doing TWW in Jamesian fashion is akin to a ‘kind of epiphany’ (101) that involves letting go of prejudices about others and embodies ‘complete re-centering of our inner lives’ (101).

A third set of essays, entitled ‘Challenges and Possibilities’, includes voices of ‘sympathetic critics’ (108) and the contributions of scholars from other fields such as cognitive science of religions (CSR) and evolutionary psychology, most of which present either new possibilities or unforeseen challenges offering new sites of engagement for TWW. Peter Feldmeier raises the question of whether TWW is possible at all when we accept the legitimacy and non-reducibility of different religious traditions. He is also critical of TWW as it has no boundaries, no locus, no living tradition, and no readership. While recognizing the role of conventional theological frameworks and doctrines in religious traditions as necessary, he raises his doubts about TWW (117). The second essay in this section, by Wesley J. Wildman and Jerry L. Martin, draws readers’ attention to the three most plausible and highly developed models of the post-axial religious category about the ultimate reality, namely, the ultimate as ‘an agential being’ (ultimate reality as personal), ‘ground of being’ (beyond the categories of existence and non-being), and ‘subordinate god’ (a personal or not-less-than-personal God or gods within a more fundamental ultimate reality). While the world religions adopt one or the other of the three understandings of the ultimate, they are also confronted with the two major problems, namely, the problem of evil and the problematic of one and many. Johan De Smedt and Helen De Cruz present CSR (cognitive science of religion) as a potential candidate which can provide common ground for conversations across religious traditions, though they do not engage with the idea of TWW directly (they do not even mention the phrase TWW).

Part IV, entitled ‘Theologizing in a Multireligious World’, explores the context of diverse religious landscapes of our times wherein one's religious identity is at threat against the experiences of religious differences encountered in our contemporary world, and weighs in on various religious sensibilities that emerge in such situations. J. R. Hustwit points to the need for recognizing the legitimacy of others’ religious experiences embedded in different traditions. He mentions four theological hypotheses he is left with as regards the ultimate: (1) the Ultimate is equally available and mediated to all humans; (2) this mediation is effected by conceptual schemes produced by communities of humans; (3) the contents of conceptual schemes keep on enlarging and transforming through dialogue and conversation; (4) one encounters truth, not at the beginning but at the end of dialogue. These considerations indicate that that ‘the only way to do theology is to do it transreligiously’ (153) and ‘to follow the truth, even if it takes one beyond the limits of her home tradition’ (153). This realization necessarily calls for dialogue with others not only because dialogue will bring about novel ideas and practices, exploding the boundaries of my horizon, but also because dialogue ‘traces the boundary that joins human language and the prelinguistic sacred’ (162). Linda Mercadante examines the religious experiences of the people called SBNR (spiritual but not religious) and states that while their experiences of the divine take place outside the organized religious spheres, they have some theological contents in common not only with other SBNRs but also with the traditional religious adherents. As Mercadante observes, these ‘theological footholds’ (195), such as spiritual experiences (like a sense of cosmic consciousness, love for religious architecture and music, etc.) and understandings about the natural world (such as awe and wonder at the natural world, concern for earth's suffering), and the authentic self (‘that can connect with cosmic consciousness or allow the universal energy to propel action’, 196), can pave way for a meaningful conversation between SBNRs and the traditional religionists, resulting in the exercise of TWW.

Part V, entitled ‘Expanded Confessional Theologies’, is a collection of essays authored mostly by well-known and some pioneering scholars of interreligious theology. Francis Clooney, one of the most celebrated proponents of comparative theology of our times, explores both the ideas and the long history of interreligious learning in Catholic tradition. As implied by the very title itself, Clooney chooses to advocate strongly the need to have walled theology. Accordingly, he offers the reformulation of theology put forth by the volume editor Martin by describing the nature of theology with walls as ‘a home with foundations and walls and windows and doors, a roof held up by the walls and – why not, a welcome mat at the entrance’ (224). The real purpose of ‘theology with walls’ like comparative theology is to encounter the religious other and treat their texts with utmost openness and respect so as to be enriched by them and to become a better and a more enriched religious person in one's own home tradition. Jeffery D. Long argues that for the adherents of the Hindu Vedanta tradition of Ramakrishna, TWW is easy to embrace not only because it is their mode of theologizing right from the tradition's inception, as its founding figure Ramakrishna was profoundly engaged in multireligious spiritual practices already then, but also because Vedanta tradition itself ‘has been rooted in the idea that ultimate reality and the truths leading to it cannot be confined to a single tradition’ (227).

This book deserves a place in the advance reading list of courses such as philosophy of religion, interreligious dialogue, comparative religion, and theology of religions, and it is a ‘must read’ for the PG programmes on inter-faith studies. This book would enjoy a long shelf life in the libraries of the universities and religious studies centres as it actively engages with the idea of how to position one's religion and process one's religious sensibilities amidst other living traditions in our contemporary society, which is increasingly and inevitably becoming multireligious everywhere.