This article examines the views and place of Izmirli Ismail Hakkı in late Ottoman thought. A prominent religious thinker, Hakkı took part in lively debates in Istanbul. He and other moderate religious thinkers were against the defenders of mere positivism in the process of modernization of Ottoman thought in the modern period. By focusing on Hakkı, the article aims to highlight the significance of central Ottoman scholars in modern Islamic thought and the debates of modernization. It pays special attention to Hakkı's attempt to reconstruct Islamic philosophical theology with a new kalam book and to his critical responses to 19th–century materialist thought, as well as to his opinions regarding other Ottoman reform projects.