One man in his environment -- Coordinates -- Intellectual history and philology -- Peripheries -- Sources and structure -- Dramatis loci -- A history of Bornu and Baghirmi as Islamic states -- The spread of Islam -- Ethnicity, religion, slavery -- Islam and traditional religions -- Conclusion -- Muhammad al-Wali -- Biography -- Works -- Reputation -- Education -- Conclusion -- The scholar's habitat -- Scholarship -- Religious leadership -- Intellectual environment: genres -- Intellectual environment: themes -- Conclusion -- Method and message -- Al-Sanusi's Sughra -- The kabbe -- Between oral and scholarly text -- Tradition with a twist -- Conclusion -- Demonising smokers -- How tobacco conquered the Islamic lands -- Al-Wali's point of view -- A folktale about the devil's piss -- From Abgar to al-Azhar -- Conclusion -- On writing -- Author and authority -- Why did al-Wali translate the Fulani commentary? -- From orality to literacy -- Knowing and the knower.