Positive psychology
Martin Seligman and Buddhist monk Thanissaro Bhikkhu have pointed out that the framework of Positive psychology is ethically neutral, and hence within that framework, you could argue that "a serial killer leads a pleasant life, a skilled Mafia hit man leads a good life, and a fanatical terrorist leads a meaningful life." Thanissaro argues that Positive psychology should also look into the ethical dimensions of the good life. Regarding the example of flow states he writes: