What is the Gulen Movement and why is Turkey's President Erdogan so convinced that the organisation and its charismatic leader were behind the failed military coup of 15th July 2016? The Gulen, or Hizmet, movement in Turkey was until recently the country's most powerful and affluent religious organisation. At its head is the exiled Muslim preacher Fethullah Gulen, who leads from a gated compound in the Pocono Mountains of the USA.The movement's central tenet is that Muslims should engage positively with modernity, especially through mastering the sciences. At hundreds of Gulen-run schools and universities, not only in Turkey but also worldwide and particularly in the United States, instructors have cultivated the next generation of Muslim bankers, biologists, software engineers and entrepreneurs. In this groundbreaking study, Caroline Tee, an expert on the Gulen Movement, analyses the complex attitudes of Gulen and his followers towards secular modernity. Considered against the backdrop of Turkish politics, Gulenist engagement with modern science is revealed as a key source of the influence the movement has exerted.