This work for the first time thoroughly examines and evaluates the life, works and thoughts of the Volga Tatar scholar and thinker Musa Jar-Allah Bigi (1875-1949). The author, a historian of the Jadid movement, while criticising earlier studies on the thinker, builds up an exhaustive bibliography and presented an extensive evaluation of Bigi’s work. At the same time, the author discloses that Bigi stands between the old and new values of his society. Through this approach, the author tries to explain Bigi’s apparently contradictory ideas: Although Bigi had a firm stand of conservative Salafi scholars such as Ibn Taymiyya, why did he defend the liberal ideas of Sufi thinkers? The author, from a historian’s perspective, examines Bigi’s thoughts about the political involvement of the Muslims of Russia, on educational reform, on the reinterpretation of women’s rights, and on religious reform in general. Finally, the author analyses the influences of Bigi’s thought upon Turkish intellectuals of his time.