Tyler Fagan

Speeding heightens the risk of traffic accidents, which are a leading cause of death. Vehicles can be fitted with a new technology, Limited Intelligent Speed Assistants (LISA), that makes it impossible for drivers to exceed local speed limits. In a chapter in Thomas Søbirk Petersen's recent book, he argues-alongside Kasper Lippert-Rasmussen, who coauthored the chapter-that LISA-enabled vehicles should be mandatory. The authors base their argument on the "Principle of Required Prohibition," according to which the state ought to regulate design of a product to reduce the harms of illegal use if it can do so without creating comparable harms or making any lawful use impossible, and if this is the most feasible and efficient way to avoid the harm caused by illegal use (2025, p. 131). In this commentary we argue that, at least in some contexts, required LISA installation represents unjustified state action because it undermines moral agency. We understand moral agency as the ability to be sensitive to and act in accordance with our own reasons, including moral reasons. States often use technology to encourage good action and reduce harm by way of our reasoning capacity, by highlighting certain reasons and adding consequences to action. However, LISA technology operates outside of the space of reasons. By removing opportunities for moral choice, LISA can erode moral knowledge and our attentiveness to morally relevant facts. In this way it goes beyond criminalization of conduct, which disincentivizes, but does not make impossible, criminal action. We conclude that LISA is not the most efficient way for a state to reduce the harm related to traffic accidents, at least in certain contexts. We recommend other state action, including other techno-regulations, that address the harms of speeding without diminishing moral agency.

This paper explores the relevance of psychiatric diagnoses to responsibility assessments, with a focus on criminal law. There is wide agreement that certain mental disorders and developmental conditions may impact one's capacity for responsible agency, but whether a diagnosis itself is relevant—and if so, how—remains unclear and controversial. A psychiatric diagnosis carries information about the mental differences or symptoms a person with that diagnosis might experience. Because of this, we argue that diagnoses are relevant to responsibility when they pick out symptoms or differences that are likely to undermine the specific capacities that matter for responsibility. We claim that where there is enough empirical evidence about the impact of a diagnosis on legal agency, a criminal court must investigate whether a defendant ought to be fully or partially excused. Intellectual disability is this sort of diagnosis. Evidence that a person has intellectual disability at the time of their wrongful act does not automatically settle the question of their responsibility, but this diagnosis requires that the court investigate the nature and degree of responsibility-relevant differences and symptoms experienced by that person at the time of the act in question.

Joshua May’s Neuroethics: Agency in the Age of Brain Science gives a clear, engaging, and philosophically rich introduction to the subject. It is a sustained and powerful defense of a bold position within the field of neuroethics, and a demonstration of what makes that field philosophically important and genuinely exciting. Despite the book's overall excellence, I have some concerns about May's call for more nuance in thinking about the connections between mental disorders and responsibility. More nuance in this regard is unquestionably welcome given the status quo, and May's thesis of cognitive continuity is both well-supported and morally urgent; however, I worry that May's "nuanced view" overshoots the mark and incurs some significant practical and conceptual costs, which we can avoid by accepting a little less nuance than May recommends.

In this chapter we explore the ethical justifications for criminal detentions prior to adjudication. Because defending pretrial detentions cannot be justified on purely forward-looking grounds, any plausible justification for pre-conviction detention must be partly backward-looking. Reflecting on the aims of the criminal law more broadly suggests that pretrial detentions, like post-conviction detentions, may be justified on “hybrid” grounds—but only if certain backward-looking retributive criteria and forward-looking instrumental criteria are met. We conclude that while it is possible in principle to justify pretrial detention, there is reason to think that much of the pretrial detention in the U.S. is not, in fact, justified. We then argue that as a result, current pretrial detention practices in the U.S. unjustifiably diminish a special sort of moral agency that is necessary for holding persons responsible in the first place.

In this paper we attempt to reply to the thoughtful comments made on our book, Responsible Brains, by a stellar group of scholars. Our reply focuses on two topics discussed in the commenting papers: first, the issue of responsibility for negligent behavior; and second, the broad claim that facts about brain function are normatively inert. In response to worries that our theory lacks normative implications, we will concentrate on an area where our theory has clear relevance to law and legal policy: juvenile responsibility.

Culpability lies at the heart of our moral and legal practices of blaming, censuring, and punishing. Put simply, an agent is culpable for an action if the action is wrongful and the agent is responsible for that action. This seemingly straightforward concept remains contested within philosophy and legal theory, however, especially in the relatively new fields of neuroethics and neurolaw. How to understand responsible agency, which agents are potential bearers of culpability in general—and for which actions—and the possible evidentiary relevance of neuroscientific findings to these topics are all subjects of active debate.

US criminal courts have recently moved toward seeing juveniles as inherently less culpable than their adult counterparts, influenced by a growing mass of neuroscientific and psychological evidence. In support of this trend, this chapter argues that the criminal law’s notion of responsible agency requires both the cognitive capacity to understand one’s actions and the volitional control to conform one’s actions to legal standards. These capacities require, among other things, a minimal working set of executive functions—a suite of mental processes, mainly realized in the prefrontal cortex, such as planning and inhibition—which remain in significant states of immaturity through late adolescence, and in some cases beyond. Drawing on scientific evidence of how these cognitive and volitional capacities develop in the maturing brain, the authors sketch a scalar structure of juvenile responsibility, and suggest some possible directions for reforming the juvenile justice system to reflect this scalar structure.

Child soldiers, who often appear to be both victims and perpetrators, present a vexing moral and legal challenge: how can we protect the rights of children while seeking justice for the victims of war crimes? There has been little stomach, either in domestic or international courts, for prosecuting child soldiers—but neither has this challenge been systematically addressed in international law. Establishing a uniform minimum age of criminal responsibility would be a major step in the right direction; we argue that such a standard ought to be guided by the best evidence from neuropsychology about the development, during childhood and adolescence, of the executive functions that give rise to morally and legally responsible agents. In light of that evidence, which suggests that the brain’s executive functions are still maturing into early adulthood, we recommend a graded structure of culpability for child soldiers.

In this chapter we will argue that the capacities necessary to moral and legal agency can be understood as executive functions in the brain. Executive functions underwrite both the cognitive and volitional capacities that give agents a fair opportunity to avoid wrongdoing: to recognize their acts as immoral and/or illegal, and to act or refrain from acting based upon this recognition. When a person’s mental illness is serious enough to cause severe disruption of executive functions, she is very likely to lack substantial capacities necessary to be law-abiding. Our analysis supports the Model Penal Code test for legal insanity over the traditional M’Naghten test, because the Model Penal Code test allows either severely diminished cognitive or volitional capacities to warrant an excuse to criminal culpability. We will provide a nuanced account of the ways in which mental illness can erode executive function, as well as an explanation as to why severe diminishment of executive functions caused by mental illness, but not some other causes, is exculpatory.

[This download includes the table of contents and chapter 1.] When we praise, blame, punish, or reward people for their actions, we are holding them responsible for what they have done. Common sense tells us that what makes human beings responsible has to do with their minds and, in particular, the relationship between their minds and their actions. Yet the empirical connection is not necessarily obvious. The “guilty mind” is a core concept of criminal law, but if a defendant on trial for murder were found to have serious brain damage, which brain parts or processes would have to be damaged for him to be considered not responsible, or less responsible, for the crime? The authors argue that evidence from neuroscience and the other cognitive sciences can illuminate the nature of responsibility and agency. They go on to offer a novel and comprehensive neuroscientific theory of human responsibility.

Skeptics about nonlinguistic mindreading often use an inferential rule of thumb—the principle of conservatism—to cast doubt on purported empirical evidence of mindreading abilities in nonlinguistic creatures. This principle, if warranted, would seem to count generally against explanatory hypotheses that posit nonlinguistic mindreading, instead favoring mere behavior-reading hypotheses. Using a test case from research with chimpanzees, I show that this principle is best understood as an appeal to parsimony; that, regardless of how one conceives of parsimony, the principle is unwarranted; and that, once we put the principle aside, the prospects for nonlinguistic mindreading are brighter than traditionally thought.