This book tells the life story of Ya‘qub ibn Ishaq al-Kindi, the philosopher, scientist, and thinker. In his lifetime he bore two titles: Philosopher of the Arabs and Descendant of Kings. Eleven centuries ago he opened a new road for Arab civilization by reclassifying the sciences and reconciling philosophy and religion. He also devised the first scale for Arab music corresponding to the modern natural scale, and he played an important role in introducing Indian numerals into the Islamic and Christian worlds. The “Scientists of Islamic Civilization” series presents the biographies of outstanding Arab and Muslim scholars and their contributions to human civilization.