This work is an analysis of one of the greatest (and largely forgotten) early Muslim theologians, Abu Mansur Muhammad ibn Muhammad ibn Mahmud al-Hanafi al-Mutakallim al-Maturidi al-Samarqandi (d. 333/944). It establishes evidence of al-Maturidi's profound influence upon Islamic theology during his time and discusses his method, theory of knowledge and theological ideas concerning the world, and the relation of God to man. Emphasizing in particular al-Maturidi's magnum opus, the "Kitab al-Tawhid", the author explains his view of the historical development of Islamic theology in light of the three elements of ta'ah (faithful obedience), bayan (elucidation) and the naql-'aql (tradition/reason) dialectic. He concludes that al-Maturidi's influence upon the overall development of Islamic theology is not only profound but original, not only in his development of Islamic theological theory of knowledge and in his scientific way of research, but also in his being able to resolve the naql-'aql conflict.