2009 reissue of the 1970 Cornell study of Islamic reform in 20th-century Indonesia which focuses on the role and influence of Persatuan Islam, an organisation which defined and promoted Islamic ideas and reform in largely modernist terms. The Persatuan Islam activities, which included publications and local reforms in the pre-WWII period, are described. Its attitudes to Christian propaganda, the Nationalist movement, and the restrictions during the Japanese Occupation and the Revolutionary Period are reviewed and its positive adjustments to the ongoing scientific, economic and political trends (NB 1960s) are noted. With glossary, listing of Persatuan Islam publications and bibliography.