Science ('ulum), as used by Sa'id and other scholars of that period, is a broad term covering virtually all aspects of human knowledge. After initial discussions of the categories of nations that did or did not cultivate science, Sa'id details the specific contribution of nine nations or peoples-India, Persia, Chaldea, Greece, Rome, Egypt, the Arab Orient, al-Andalus, and the Hebrews. He includes the names of many individual scientists and scholars and describes their various contributions to knowledge, making his book a significant work of reference as well as history.