When someone is found guilty in the eyes of the law, how do we know if we are before an evil person or a sick person? How can the law find more reliable, and fairer, criteria in order to attribute responsibility and, consequently, culpability? This book argues that neuroscience can make a significant contribution to better justice be performed. According to the authors, whose academic background is in Philosophy, “[N]euroscience is both relevant to responsibility and consistent with our ordinary “folk” conceptions of it. Evidence from cognitive science and neuroscience can illuminate and inform the nature of responsibility and agency in specific, testable ways.” (p.12) More specifically, “[T]he pertinent question is not whether brain science can inform responsibility assessments, but in which sort of cases, and to what extent.” (p.9)

         In order to achieve this there are two key steps: first, to inform what exact capacities are at stake and how they can make us responsible — with findings from neuroscience (p.12); second, to reconcile two different perspectives of agency, one assumed in the realm of criminal law where human agency is basically free and reason-based, and another predominant in contemporary brain science “where actions are governed by the mechanistic churn of an immensely complex physical system.” (p.12,13)

         The capacities that are at stake, and are reflected in criminal offenses and verdicts, concern a particular set of cognitive and volitional capacities, which in neuroscience translates as executive functions (attentional control, planning, inhibition, and task switching). These are therefore given centre stage in this book where recent findings in neuropsychology are linked with the field of law (both legal theory and criminal law (Ch.4), and even in our everyday assessments (Ch.3)). Bridging neuroscience and the legal realm the authors develop a philosophical approach on theories about free agency and moral responsibility.

         What is important to be said is that the book’s approach on the brain is very literal, being their main concern the brain itself, the organ. They assume themselves as mind-body materialists, more specifically, physicalists, ie. brain states, events and processes are mental components required for responsibility. Privileged concepts are neuron, axon, white and grey matter, cortical areas, and processes such as activating, modulating and inhibiting (p.91) Their goal is to find a concrete and measurable locus of human responsibility. (p.38) The interaction of the brain with its surrounding environment is not considered, the interaction between the brain and the rest of the body is also disregarded and the ability for the brain to alter itself (brain plasticity) is not addressed. Executive functions are the main axis of the book’s argument allowing the authors to develop a theory of responsibility based on it and subsequently determining what sorts of scientific evidence is relevant to assess criminal responsibility. (p.70) Consciousness is also taken as a sign of executive engagement being ultimately reduced to the brain. (p.113) More radically, authors state that it is executive engagement rather than any relation to consciousness that does the real work in giving us the capacity to be responsible. (p.131) They proceeded by exploring explore several case studies (Ch.7) and addressing specifically juvenile responsibility (Ch.8).

         In Chapter 9 we find the pragmatic and applicability of the proposed executive theory of responsibility in justifying the insanity defence’s role while also suggesting ways in which it can be reformed — within the scope of the United States’ legal system. (p.177,178)

         A significant and highly relevant discussion follows on whether the author’s theory of responsibility can shed light on the question of what relevance, if any, exists between clinical judgements of mental illness and legal judgements of insanity or incapacity. (Ch.9) Should, for example, psychopaths qualify as exempt from criminal responsibility or at least as eligible for diminished-capacity status? What are the grounds to establish a ‘legal’ concept of insanity? The authors argue that executive functions are key to bridge the medical diagnostic ‘mental illness’ with the legal concept of ‘insanity’. (p.196,197)

         When it comes to mental health, from a legal standpoint of view, how does this difference between a medical diagnosis and a legal declaration of insanity operate? Very pragmatically they openly state that “[v]erdicts of ‘guilty, but mentally ill’, which are fairly common in the United States, are inappropriate for those who are legally insane.” (p.197) For example, when before a psychopath and a schizophrenic, when it comes to declare legal insanity, it is more legitimate to do so concerning the schizophrenic because executive functions are known to be affected more directly. This means that ultimately, psychopathic offenders exhibit serious moral and empathy problems but they are able to conform their behaviour to laws and moral norms. They perhaps do not care about the law but the law only asks the psychopath to obey it. A schizophrenic may be incapable of understanding or following the law because of the possibility of having his/her executive functions severely compromised (detected in brain and behaviour): “persons deemed legally insane are unlikely to be able to manage their own lives, and they are at risk for recidivating.” (p.197) That is why authors defend that most legally insane defendants ought to be admitted to a hospital. ‘Mental illness’ should not be an excuse to exempt all who are medically deemed so and it should not be the decisive factor to declare someone guilty. What the authors argue is that ultimately, the ‘legal insanity’ status, established through a careful examination of executive functions, taking in consideration a medical-scientific diagnosis of ‘mental illness’, can be useful leading to a more just and humane criminal assessment of responsibility and culpability — and, eventually to a more effective rehabilitation.

         In conclusion, the book does make a compelling case for the benefits of bringing together neuroscience (a fast-growing field of research) and, legal theory and criminal law. Being a recent inter-disciplinary crossover there is much ground to be covered and many questions to explore. The authors’ physicalist approach of the brain is debatable however, the potential reader may find in this book a door to a new area of research that hopefully will find key developments in the near future.

© 2019 Diana Soeiro

Diana Soeiro (Philosophy PhD) is a researcher at ISCTE-Lisbon University Institute and at University of Lisbon. Updated information: www.linkedin.com/in/DianaSoeiro