Cohoe's edited collection of essays tracing Aristotle's De anima (On the Soul) from its early chapters to its conclusion is one of the most useful, scholarly and thoughtful approaches to this important text I have seen to date. In breadth of material covered, depth of scholarly insight and choice of contributors, Cohoe's collection achieves something of real value I have not experienced before, at least for a commentary on De anima: a textual roadmap that walks readers through passage and paragraph in a fashion that builds not merely concept upon concept, but also builds in a discussion of the issues with which Aristotle wrestled, the predecessors he is at pains to present respectfully (yet critically) and the thoughtful, sophisticated and novel ideas for which Aristotle is often not adequately credited. It is an easy thing to recommend this book – and not just to Aristotle scholars. It is a harder thing to capture all that makes the collection so worth reading; hence my approach will be to offer a few observations and illustrations intended as markers along a road that largely provides its own direction.

In the introduction to ‘the nature and goals of this guide’ Cohoe explains that, as opposed to the late twentieth-century strategy of attempting to situate Aristotle ‘in relation to dualism and materialism’ (p. 1), his aim is to engage a set of scholars who read De anima in the light of Aristotle's own stated (or apparent) intentions. Distorted and/or under-appreciated in the dualism versus materialism debate, Cohoe writes that his approach cleaves more closely to ‘an investigation into how all these biological phenomena [the activities of living things] can be given a unified explanation in terms of a single principle, psyche, soul, the form by which something lives’ (p. 2). Cohoe's approach, in other words, is to set aside our biases about where Aristotle ‘fits’ with respect to these debates, a point he emphasises, remarking that he hopes to ‘capture Aristotle's views in their complexity’ by avoiding philosophical (or theological) commitments that sometimes only obscure interpretation. It is Cohoe's roadmap strategy that makes capturing the complexity and originality of Aristotle's view of psyche possible, offering readers a way to place him among his predecessors and successors in a fresh light.

Cohoe accomplishes this goal in two mutually reinforcing ways: first, he has selected scholars who make their focus single chapters from De anima, including careful studies of the issues, arguments and implications relevant to a specific part or theme of Aristotle's work. Second, Cohoe's roadmap strategy allows readers to follow Aristotle in a way that feels organic – that is, that stays with the text without the detritus of the debates that have tended to overshadow it. Although chapters move from scholar to scholar – and there are disagreements –, the text on the whole retains a narrative quality that invites a sense of unencumbered comparison among its contributors. This is not to say that the vital work of twentieth-century Aristotle scholars has been abandoned; but it is to say that Cohoe's approach offers a refreshing new way to look at an ancient text without pretext or given conclusions. While attempts to fit Aristotle into the Christian dualism of St Thomas or the materialism of some future biology of mind tend to ignore his sustained efforts to engage his predecessors, Cohoe's roadmap strategy provides space to writers like C.D.C Reeve, J.W. Carter and C. Shields to explore Aristotle's dialogue with the past, illuminating the direction Aristotle ultimately takes with respect to psyche as the form of a living thing.

By the time we arrive at C. Frey's ‘Aristotle on the Soul's Unity’ (Chapter 5), we have a much clearer idea why Aristotle settled on a view of living organisms as ‘substances most of all’ and what ‘substance’ means in the context of Aristotle's metaphysics with respect to psyche. Indeed, Frey's preliminary discussions of ‘Ordered Series: Souls and Figures’ along with ‘Presence in Capacity’ illuminate what I take to be the centrepiece of Frey's essay and De anima itself, the section titled ‘The Unity of the Soul’, precisely because the complexity, but also the coherent development of Aristotle's hylomorphism, is so well laid out in previous chapters. Frey can now show us why ‘[a] living organism does one thing – it lives’, why ‘to live’ for non-human animals ‘is to perceive’ and why the soul of any living organism is the ‘cause of an organism's bodily unity’ (pp. 102–3). It is thus from here – a definition of ‘soul’ established as metaphysically, biologically and functionally coherent – that we are prepared to investigate a series of hierarchically ordered capacities associated with being a living thing. Here too Cohoe's textual roadmap follows De anima not merely with respect to the order of the text, but by making it clear that this order develops in accord with a hierarchy of capacities beginning with those shared in common by all living things, moving ‘upwards’ towards capacities shared only by some, and ultimately to nous, a capacity reserved to human beings.

A fine example of the way in which Cohoe's approach enhances our grasp of concepts and arguments concerning psyche's various capacities can be found in J. Gelber's ‘Aristotle on Seed’. ‘Why are nutrition, growth, and generation all activities and functions of the same psychic capacity?’ (p. 104). She argues that ‘the way Aristotle conceives of these physiological processes is a consequence of more general metaphysical commitments’ (p. 106). How we understand these commitments is illuminated by Frey, a point that, in turn, lends itself to Gelber's discussion of ‘seed’, just as Gelber's consideration of Empedocles’ view of generation (p. 108) is lent depth by Reeve's discussion of Aristotle's hylomorphism. That Gelber's ‘strategy has been to focus … on the underlying physiological basis of the functions and activities [qua nutrition, development and generation] rather than their more abstract and formal characterizations’ (p. 121) recommends Cohoe's overall approach: neither Gelber's nor the essays that follow concerning the capacity for perception, imagination, reflection or thought are well-cast on one side or the other of the dualism-materialism debate. Rather, the subtlety and sophistication of Aristotle's view of psyche, its place within the larger aims of his metaphysics, his view of causality and his teleological commitments are shown to have their own internally coherent logic – as well as their own conflicts.

Indeed, part of the complexity we are in danger of missing in the quest to situate De anima in the dualism–materialism debate emerges from differing interpretations of nous or, as Cohoe puts it, ‘the power of understanding’ (p. 229). Really, however, there are two hazards: the first misinterprets nous by insisting on a dualist notion of its separability from the body, and the second, the ‘conventional theory’, makes all human activities ‘dependent on the body’ (p. 229). In ‘The Separability of Nous’ Cohoe rejects both, exploring instead Aristotle's claim to ‘an affection that is proper to the soul and not shared by the body: noein’ that distinguishes animals from humans (p. 229). That is, while Cohoe adopts an interpretation of nous that appears more consistent with dualism, what his careful reading of De anima illuminates is that we will likely get no satisfaction about the meaning of ‘separability’ without considering it in the light of Aristotle's metaphysics, and that for Aristotle nous is a power unique to human beings because it meets a specific set of criteria (pp. 242–3). As Cohoe readily acknowledges, a number of questions persist that defy any easy recruitment of nous, for example, to St Thomas’ concept of a Christian soul (p. 243, p. 245), even as they bear comparison to Plato's account of a tripartite soul in Republic. Cohoe suggests that questions like ‘[w]hat would it mean for only nous to persist?’ (p. 243) and ‘[w]hat is the life and activity of human nous … like, apart from the body?’ (p. 244) are likely to occupy scholars into the future even if ‘Aristotle is committed to the possibility of continuing human intellectual activity’ (p. 246).

Although I have done little justice to most of the work that comprises this collection – much less to differences of view –, suffice it to say that this Critical Guide is eminently worth reading. Aristotle scholars will find it a refreshing departure from twentieth-century debates, and new readers of ancient Greek thought will find Cohoe's roadmap approach especially readable in virtue of the organic progress of Aristotle's ideas, his engagement with the past and his persistent optimism about the possibility of knowledge concerning psyche.