This book is a carefully crafted collection of essays which questions the view that scientific psychiatry ought to model itself on physics. It advocates multilevel and pluralistic strategies in psychiatric research rather than reduction of the kind physics has exemplified.

It is a multi-authored and interdisciplinary book but manages to avoid the disjointed voices and cross-disciplinary communication problems which always threatens such ventures. This is important because reduction gains much of its appeal through its transparency, and arguing for complexity and pluralism in scientific psychiatry is not going appeal to many scientists if it involves signing up to murkiness.

The authors – psychiatrists, psychologists and philosophers – seem to be genuinely talking with each other and gaining clarity and the editors have managed to achieve a dialogue between disciplines. Kenneth Kendler's voice in particular suffuses the pages – encouraging the philosophers to use psychiatric examples to test their thought experiments and reminding psychiatrists how hard we have to think to get the foundations of our subject secure. The book (thankfully) is no final ‘philosophy of psychiatry’. I found it hard going in places (technical and wordy) but certainly felt it repaid the effort.

The book is split into three themes: explanation, phenomenology and nosology. Each essay is followed by a commentary, and a helpful introduction and epilogue by the editors frame the essays.

Psychiatry needs to be explanatory if it wants to do more than merely describe. Up until relatively recently philosophers of science have taken physics to be the ideal model of explanation with other areas of knowledge ‘explanatory’ to the extent that they approximate to physics. The ‘logical positivists’ took this view and though few scientists held to it in pure form, the influence is detectable to this day and has produced a lot of ‘physics envy’ in the human and biological sciences. This physics focus has shifted in recent philosophy of science and the publication of a book entitled How the Laws of Physics Lie by Nancy Cartwright in 1983 must be considered a watershed. Cartwright argues for a pluralistic, ceteris paribus approach to causation and rejects universal accounts modelled after the physicist's analysis of one billiard ball impacting upon another. Underpinning this is a view of the world as ‘dappled’ – even messy – rather than awaiting reductive explanation with laws having universal scope.

The essays on the theme on explanation have much of the air of Cartwright's philosophy of science. Complexity is emphasized. The philosopher-physician Kenneth Schnaffner provides a useful summary of how complex molecular explanation of behaviour is even in the worm C. elegans – a massively analysed model organism. The philosopher Dominic Murphy laments the difficulties psychiatry experiences with reductive theoretical explanation and concludes that, though he regards gene-driven explanations of human behaviour to have a prime status, there are probably not many of them to be had in psychiatry.

Following that note of scientific lamentation come two very interesting essays by prominent philosophers working on causation: James Woodward and John Campbell. Both essays advocate what they call an ‘interventionist’ model of causation. They hope this model can liberate psychiatry from being beholden to the image of billiard-ball causation and the associated view that psychological or social kinds of explanation are necessarily inferior to molecular biological kinds. The model is technical, but if I have understood it correctly, it invites us to judge a causal explanation entirely from the perspective of whether an intervention can ‘make something happen’ – control or manipulate some aspect of the world – rather than whether it meets criteria derived from physics. Imagine stepping onto planet earth as an intelligent alien and surveying how humans make things happen. Amongst other activities that visitor would find humans altering their bodies through ingesting chemicals, changing each others motivations through persuasion or deception, altering each other's access to nutrition and power through changing forms of social and economic arrangement, enforcing laws, and so on. This ‘dappled’ world, Woodward and Campbell, suggest is the world. There is no fundamental causal level that we should be seeking, only causal knowledge in the form of interventions which make things happen. Physical interventions can be the best way of getting things to happen but they are not necessarily so and there is no a priori reason for privileging them. This pluralistic account of causation encourages psychiatric research to take dappledness at face value. The message is: develop ceteras parabus models of psychiatric phenomena and use these models to do things. It calls forth a type of pragmatic, interdisciplinary psychiatric engineer.

There is much of interest in this approach. From a research perspective multivariable statistical techniques have made major advances and are permissive with regard to variables across domains. Research paradigms are increasingly involving large-scale gene–brain–environment studies and will need a theoretical framework for interpreting results. The ‘interventionist’ approach to causation is likely to be influential here. From a clinical perspective it is also attractive because the emphasis is on finding reliable treatment technologies without bogging down in questions of treatment mechanisms. It is a toolbox approach to psychiatric explanation or what Campbell calls a ‘control panel’ approach.

I found this very interesting and germane to psychiatry. Here is not the place to scrutinize the technical adequacy of the model. In general terms one might wonder whether epidemiologists have been thinking this way about causation for a long time already (albeit less philosophically) and one might have concerns about the model of explanation depending too much upon human interests and thereby abandoning science's aspiration to gain a view of the world independent of those interests. But this is probably less a concern in the context of psychiatry (a science of the human being). When it comes to getting scientific explanations of pathological human behaviour as a whole perhaps we are better off getting insights from piecemeal scientific knowledge of how human behaviour can be manipulated and controlled. The reductive theoretical accounts of the human being (Freudian, Marxist, Darwinian, Neural, etc.) overreach themselves for sure.

But of course psychiatric knowledge is not only about manipulation and control. The second theme of the book explores a different kind of knowledge germane to psychiatry – phenomenology. Josef Parnas and Louis Sass together with a commentary from Thomas Fuchs call this knowledge of the structures subjectivity and argue persuasively that exclusively operationalized approaches to psychopathology (DSM, etc.) have had the effect of veiling the ‘autonomy’ of this kind of psychiatric knowledge. Phenomenology does not just blow off into the atmosphere once it has been ‘captured’ with operationalized criteria: this would be to let the slave become the master. Phenomenology is an ends – not a means. The authors go on to give an outline of phenomenological method and an application to the structure of schizophrenic consciousness.

There is something fragile about phenomenology: it requires a kind of living contact with thinking and clinical experience to be at its best and I'm uneasy with attempts to present it as a method or as textbook knowledge – it can sound hollow.

What is interesting is that Parnas and Sass have been applying a type of lived phenomenological approach in empirical research using cohort designs. In this research clinicians have used a semi-structured scale to guide judgements about self-experience in first-contact non-organic patients. The scale is oriented around self-experiences with a quality described by Parnas and Sass more richly in other publications. These self-experiences at first presentation are strongly associated with the development of schizophrenia and schizotypy five years later. This is a fascinating return to the debate over ‘first-rank symptoms’. Schneider famously emphasized their importance for schizophrenia but he refused to make sense of them in terms of self-experience. Following Jaspers he regarded them as ‘un-understandable’ and simply operationalized them. Parnas and Sass rebuke Schneider in this respect. Their view is that Jaspers/Schneider unnecessarily limited the inquiry into self-disorder in schizophrenia and promoted an exclusively criteriological approach which undermines phenomenology – an ironic consequence given Jaspers and Schneider are psychiatry's most famous phenomenologists.

The phenomenology section is also concerned with the important question: can phenomenology explain the world or only describe it? Jaspers/Schneider tended to take the latter view. Parnas and Sass criticize that position using the philosophical resources of Husserl's constitutive phenomenology. For Husserl structures of consciousness have implicative relations to each other in a way analogous to logical implication. Logic does not describe the world, it structures or constitutes the world. Parnas and Sass argue something similar about phenomenology. They make reference to psychopathologists who disregarded Jasper's limiting of phenomenology to description. In particular they mention Eugene Minowski's concept of a ‘generating disorder’ in which a pathological phenomenological structure can give rise to symptoms in a manner analogous to how an organic disturbance gives rise to symptoms.

We have a bias in psychiatry. We tend to speak as if organic or psychological nature is our sole point of orientation and that phenomenology is a referent only in so far as it describes, or marks off, the organic or psychological realms. This is one sided. Phenomenology provides an independent validating realm and Parnas and Sass are right to highlight it. We can know a mental state is pathological with reference to the phenomenological realm without necessary reference to the organic or psychological realms. In clinical practice we do this all the time and our classifications of mental disorders depend upon it. Parnas and Sass though, I think, reach a block in their exploration of this realm because they do not expand phenomenology to include ethics and philosophical anthropology. They talk about structures of subjectivity or the constitution of subjectivity rather than the normativity of the human being or the constitution of the human being. It is ethics which explains the fact that psychiatry has developed laws – laws which permit or prohibit probably the most momentous interventions psychiatrists make in the lives of their patients: deprivations or restrictions of freedom with the goal of restoring or increasing freedom. It is philosophical anthropology which gives provisional/somewhat metaphorical explanations of what our nature as a human being is, what mental disorder can teach about this nature, and what the appropriate aims of psychiatry should be.

I have discussed symptoms and that brings us nicely to the last section of the book: nosology. Psychiatry cannot just speak of symptoms. The term ‘symptom’ means an indicator of something else, which, by convention in psychiatry we take to be disease (greek: nosos). The problem psychiatry has – identified decades ago by Schneider – is that for all but the organic mental disorders we have no stable referent for disease construed as organic or even psychological dysfunction. This, together with the heterogeneity of symptoms which we regard as potential indicators of psychiatric disorders, leaves our nosological concepts vulnerable. Kenneth Kendler and Peter Zachar in their essay on nosology use the striking phrase ‘incredible insecurity’. Yet both Kendler and Zachar want to avoid abolishing nosology. Zachar, in one essay, advocates a kind of pragmatic approach to diagnostic categories suggesting that they are ‘real’ but not ‘true’ reflections of nature. This approach is rather similar to that taken by Schneider decades ago. Kendler suggests that we try to solidify our nosological concepts by both broadening them where appropriate and running them through evolutionary ‘tape rewinds’. Try this thought experiment: would ‘schizophrenia’ re-appear on the human scene if we rewound to the early history of Homo sapiens and pressed ‘play’, allowing human history to take a different course? Alas, Parnas comments, this is a thought experiment only and cannot be tested: mental disorders are too soft to leave a fossil record. But is it just a thought experiment? Homo sapiens has developed in all sorts of different directions across the planet – diversifying out of the rift valley into a multitude of forms of life. These are in front of our eyes: human cultures and ethnicities. Anthropology, under the influence of philosophical doctrines of relativism, has been emphasizing the radical diversity of human cultures and is now, having deconstructed any notion of human nature, seeking to re-invent itself. Perhaps we can use cultural diversity to test our nosological and phenomenological concepts. We may get a purer idea of, say schizophrenia and bipolar or unipolar affective disorder, when we look for invariance across culture and ethnicity; when we immerse ourselves in the manifestations of the disorders in different cultures and ethnicities and then, drawing back, try to get into focus common phenomenological structures. Perhaps transcultural, anthropological psychiatry can, ironically, save us from nosological nihilism.

This is a high-quality publication achieving genuine dialogue between psychiatry and philosophy. It is exciting to see first-rate philosophers engaging with psychiatry and with leaders of academic psychiatry taking philosophy seriously. The tone and orientation of this book is one of complexity and pluralism in psychiatric explanation: it conjures up the image of the subtle doctor.