In their recent book Unfit for the Future, Persson and Savulescu make a heartfelt plea for the increasing necessity of “moral enhancement”, interventions that improve human capacities for moral behaviour.3 They argue that, with all the technological advances of the 20th and 21st centuries, the sheer scope of horror that humans can now potentially wreak on their neighbours or the world is staggering. Hence, we are morally obliged to use interventions at our disposal to prevent such atrocities. However, as we learn more about human behaviour and decision-making, the argument that we are morally obligated to morally enhance our friends, neighbours, or countrymen starts to fall apart. For us to be more moral requires more than sharpening our reasoning capacities so that we can more effectively recognise what is better or increasing personal motivation so that we are more likely to do what is good. It requires that we all agree on what the good is and how to achieve it, and that there are no social, cultural, physical, or psychological impediments that prevent us from recognising the good or acting on it. To illustrate my position, I use the phenomenon of self-radicalised terrorists as a case study. In particular, I focus on how historians, psychologists, sociologists, criminologists, and political scientists understand the process of self-radicalisation, who self-radicalises, and why, and what all this tells us about it should be “treated”. Part of my purpose in working my way through this case study is to demonstrate that many philosophers misunderstand or over-simplify the science behind so-called immoral actions; consequently, their discussions of whether to enhance someone's morality miss their mark.