characteristic of polymaths. For individuals, Ahmed says, specialisation is dehumanising and stifles their full range of expression whereas polymathy "is a powerful means to social and intellectual emancipation" which enables a more fulfilling life. In terms of social progress, he argues that answers to specific problems often come from combining knowledge and skills from multiple areas, and that many important problems are multi-dimensional in nature and cannot be fully understood through one specialism. Rather than interpreting polymathy as a mix of occupations or of intellectual interests, Ahmed urges a breaking of the "thinker"/"doer" dichotomy and the art/science dichotomy. He argues that an orientation towards action and towards thinking support each other, and that human beings flourish by pursuing a diversity of experiences as well as a diversity of knowledge. He observes that successful people in many fields have cited hobbies and other "peripheral" activities as supplying skills or insights that helped them succeed. Ahmed examines evidence suggesting that developing multiple talents and perspectives is helpful for success in a highly specialised field. He cites a study of Nobel Prize-winning scientists which found them 25 times more likely to sing, dance, or act than average scientists. Another study found that children scored higher in IQ tests after having drum lessons, and he uses such research to argue that diversity of domains can enhance a person's general intelligence. Ahmed cites many historical claims for the advantages of polymathy. Some of these are about general intellectual abilities that polymaths apply across multiple domains. For example, Aristotle wrote that full understanding of a topic requires, in addition to subject knowledge, a general critical thinking ability that can assess how that knowledge was arrived at. Another advantage of a polymathic mindset is in the application of multiple approaches to understanding a single issue. Ahmed cites biologist E. O. Wilson's view that reality is approached not by a single academic discipline but via a consilience between them. One argument for studying multiple approaches is that it leads to open-mindedness. Within any one perspective, a question may seem to have a straightforward, settled answer. Someone aware of different, contrasting answers will be more open-minded and aware of the limitations of their own knowledge. The importance of recognising these limitations is a theme that Ahmed finds in many thinkers, including Confucius, ʿAlī ibn Abī Ṭālib, and Nicolas of Cusa. He calls it "the essential mark of the polymath."