In the twentieth century, the rise of science and secularism became major preoccupations for countless religious thinkers, Muslim or otherwise. Among them was Said Nursi, an influential Kurdish-Turkish thinker who grappled with such timeless questions as what is a human being, and what constitutes true knowledge? After living through the collapse of the Ottoman Empire, and spending years in Siberia as a prisoner-of-war, Nursi spent the second half of his life trying to expand the insights of traditional Islam in ways that were relevant to modern times. The result was his 6000-page Risala-i Nur (‘Epistles of Light’), which he smuggled out of the remote Anatolian village where the secularizing rulers of republican Turkey had condemned him to internal exile. In this episode, we draw on the Risala-i Nur to explore Nursi’s ideas about knowledge, science and the human condition. Nile Green talks to Mustafa Tuna, the co-author of A Glossary of Islamic Terms in the Light of the Risale-i Nur (Neşriyat, 2021).