How much nuance is too much?

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.