This book tells the life story of Abu al-Hasan al-Qurashi al-Dimashqi, known as Ibn al-Nafis, a polymath and genius of Arab medicine who turned anatomy into an independent science, revealed the secrets of the heart, and discovered the lesser circulation of the blood four centuries before the English scientist William Harvey discovered the greater circulation. The “Scientists of Islamic Civilization” series presents the biographies of outstanding Arab and Muslim scholars and their contributions to human civilization.