Theological work on animals and animal ethics is still well described as an emerging field despite enormous advancements in the last 50 or so years. Clair Linzey's Developing Animal Theology: An Engagement with Leonardo Boff further vitalizes the discipline as she brings a key Catholic thinker into the conversation. In it, she asks what, if anything, Boff's writings contribute to “a fully satisfying theology of sentient creatures, one that builds on the foundational insights of animal theology” (p. 14). By foundational insights, she refers primarily to the work of British theologian Andrew Linzey whose writings since the 1970s set the agenda for greater ethical inclusivity in such influential works as Animal Theology (1994), Animal Gospel: Christian Faith as if Animals Mattered (1998), and Why Animal Suffering Matters: Philosophy, Theology, and Practical Ethics (2009). Clair Linzey begins with an overview of this work (pp. 1–14).On the surface, her study of Boff in the context of animal studies is unexpected, given she ultimately finds his theology insufficient with respect to other-than-human species. It is, as she puts it, an unfinished journey (p. 161). In parts of the Boff corpus, he comes close to consideration of animal well-being, but “although the framework is there, he does not quite make that leap” (p. 104). He fails to “take on board the notion that the pain and suffering of fellow creatures needs to be included in any consistent and thoroughgoing liberatory work in theology” (p. 89). Yet, his attention to liberation, the poor, and Saint Francis of Assisi includes conceptual resources useful for articulating a robust animal theology. In such Boffian emphases as divine concern for the peripheries/margins, incarnation as “being-for-others” (pp. 47–49), and a Trinitarian approach to social concerns, to name only a few key ideas, she finds the bases “for a liberation theology of creation, and especially animals, even though this is not explored directly by Boff himself” (p. 58).She follows the evolution of Boff's thought toward ecological concerns, which he viewed as an extension of his liberation theology “in that both the cry of the earth and the cry of the poor are rooted in the will to dominate, which victimises both the environment and the poor” (p. 30). Though his work offers little about improving the status of animals directly, it is proving to be significant in turning Catholic ethical thought toward creation generally, and it apparently helped shape Pope Francis's ideas in Laudato Si’ in particular (pp. 126–134). Though it is “insufficiently attentive to the animal issue . . . he has been a catalyst for more creation-friendly, and even animal-friendly, thought within the Church” (p. 167). But more than his environmental writing, it is his focus on the liberation of the poor and Saint Francis of Assisi that provide “the most fertile ground for considering the moral status of animals” (p. 30; cf. p. 74).Boff's failure to articulate the full implications of the liberation he envisions is explored throughout. The kingdom of God, the reordered world, is, for him, “a total, global, structural revolution of the old order” and “a liberation from sin, from its personal and cosmic consequences, and from all other alienation suffered in creation” (Jesus Christ Liberator; cited in Linzey, p. 53, her emphasis). This raises the possibility of an all-inclusive theology, though Boff does not exploit this potential, instead leaving “this part of his thought unexplored” and so failing to “follow through the logic of his position” and “consider the relevance of the kingdom to nonhuman beings” (p. 54).The limitations of Boff's vision are a consequence of his narrow focus on humans (pp. 48–50 and throughout). It is evident, for instance, in his appeal to the Jungian notion of the collective psyche to explain the incarnation and Christ's identity with all humanity. Defining the incarnation so narrowly, linking it to a specifically human psychology, overlooks the broader implications of the opening chapter of John's Gospel, which presents Christ becoming sarx, flesh, and thereby identifying with all creatures: “If what is redeemed in Jesus is the collective human psyche, it is hard to see how creation as a whole is redeemed” (p. 50). Boff's cosmic Christology reflects the influence of Pierre Teilhard de Chardin and finds support in such biblical texts as Ephesians 1:10, Colossians 1:16, and John 1:14, but there is “little discussion” of other-than-human creatures. For Linzey, it seems the cosmic Christ presented by Boff “is both everywhere and nowhere” (p. 51).There is much to applaud in this innovative study, but I highlight just three features of note. To begin, one of Linzey's more intriguing ideas is her reconceptualization of the Trinity as Gentleness, Solidarity, and Fraternity (Chapter 7). This language is at the heart of the inclusive liberation theology she envisions and is an expansion of Boff's work on Saint Francis (pp. 63, 147). The result stresses a more creation-friendly and creature-friendly understanding of the Godhead (p. 151). While holding to a traditional/orthodox understanding of the Trinity, this presentation of the Father as Gentleness, the Son as Solidarity, and the Holy Spirit as Fraternity “highlight[s] the different ways in which we experience God's love” (p. 151). Further, inspired by Boff and the biblical witness, it helps us “glimpse something of the divine in relation to all creation” (p. 153; see further pp. 151–153, 159, 167).Second, her efforts to distinguish the connected but disparate concerns and priorities of ecological and animal theology—a discussion emerging largely from her critique of Boff's Ecology and Liberation: A New Paradigm (1993; English translation 1995)—is welcome. As she explains in various places, the former's attention to sustaining holistic systems as opposed to consideration of individual animals within them is more consequential in its implications than many realize (p. 34; cf. pp. 10, 174). She devotes a full chapter (pp. 85–117) to questions stemming from these different disciplines.Third, her attention to region-specific concerns in her theological work on Boff and animals is an instructive model (see, e.g., the series of interviews in the appendices, pp. 170–194). Boff is a contextual theologian (pp. 35, 77, 99–100, etc.), and Linzey introduces readers to the Brazilian setting that informs his writing (pp. 35–38). This illustration of contextually sensitive animal thought is helpful, serving to remind readers that regional/national cultural, political, and social issues shape animal welfare efforts.This thoroughly researched and innovative study is a valuable contribution to the field and is sure to (or at least ought to) prompt further attention to the place of animals in Catholic and liberation theological discourses in the years to come. Highly recommended.