The politics of wellbeing and the new science of happiness have shot up the agenda since Martin Seligman coined the phrase "positive psychology". After all, who does not want to live the good life? So ten years on, why is it that much of this otherwise welcome debate sounds like as much apple-pie - "work less", "earn enough", "keep fit", "find meaning", "enjoy freedoms"? The reason is not, ultimately, cynicism. Rather, it is because a central, tricky...