Sara Brill's new book develops her argument for understanding ‘shared life’ as central to Aristotle's ethics and politics. By focusing on this notion of shared life, she seeks to establish the connection between Aristotle's ethical, political, and zoological works in order to ground her emphasis on the essential animality of human society in Aristotle's conception. Her argument turns on a distinction between bios, a ‘way of life’ that we can choose or reject, and zoē, ‘life itself’ (3), and she is committed to establishing the generally unrecognized significance of the latter in Aristotle's ethical thought. The volume is divided into three parts. The first (‘Shared Life in Aristotle's Ethics and Politics’) concentrates on developing an account of Aristotle's concept of ‘shared life’ in the ethical and political works in such a way as to establish the importance of the zoological perspective. Here, Brill argues that shared life is at the heart of many of the central concerns of the Nicomachean Ethics, including his account of friendship. This is not simply sharing of goods or communal living: ‘Because living in its authoritative sense is perceiving and thinking, sharing one's life is sharing in perception and sharing in thinking’ (52). Brill finds a similar focus on shared zoē in the Eudemian Ethics, and the suggestion that our self-awareness and self-concern depend on the presence of others. She further develops her central claim: for all that Aristotle makes repeated assertions of human exceptionality, he also adopts a zoological framework of analysis that locates human friendship within the category of ‘animal attachment’, albeit as a special case. Human society is distinguished from animal society, but primarily as an intensification of the animal, rather than as a rejection of it. As Brill notes, setting up some of the critical analysis found in the third part of the book, her emphasis on community helps to highlight both its fragility and the consequences of exclusion. This is an idea she explains further in her analysis of shared life in the Politics: ‘if Aristotle's ethics show us the most vivid form of shared life, his Politics shows us the conditions of its destruction’ (92). Brill considers two extremes of shared life to be found in the Politics. Aristotle rejects communism for the sake of the philia that lies at the heart of a true community. His account of tyranny, meanwhile, can be understood as an analysis of a polis lacking a meaningful presence of shared life or the common good. The second part of the book concentrates on fleshing out the detail of the zoological perspective at the heart of Brill's argument by focusing on the zoological works in particular. She makes the sensible point that, while Aristotle's zoological works may be inaccurate in biological detail, they nevertheless help us to understand his own thinking about the nature and relationship of intelligence and life. Beginning with the History of Animals, Brill looks for the political in Aristotle's biological, and argues that he conceives of animal sociality in terms of its various manifestations of the political bond of a common task. It is within this context that we should situate even shared human life. This is not to say that humans are not to be distinguished from animals: what marks humans out is the fact that they can choose their way of life (bios). But this choice does not liberate them from the fact of their animality. For this reason, analysis of Aristotle's politics, and of the polis itself, should be informed by an awareness of his zoological sensibility. At times in the detail of Brill's own analysis, this zoological emphasis seems to fade into the background, but her central claim remains that human politics is an intensification of animal sociality, rather than a rejection of it. The third and final part presents an intriguing exploration of intersections between Brill's account of Aristotle's zoē-politics and modern critical theory (her volume is published in the interdisciplinary series Classics in Theory). She first addresses the connection between Aristotle's commitment to private ownership and his eugenics legislation, noting the double mean of tokos as both ‘interest’ and ‘child’. She is particularly interesting on Aristotle's concern with the threat of uncontrolled or excessive reproduction. She then turns to an analysis of Aristotle's account of – and ambivalence towards – the maternal bond as central to his understanding of human communities and, especially, friendship. The two chapters of Part III are particularly compelling; I look forward to seeing further approaches to Aristotle, and ancient philosophy in general, along these lines.