The Prolegomena of Ibn Khaldun are in many ways the most remarkable manifestation of Islamic philosophical thought. Not only did Ibn Khaldun sum up the accumulated knowledge and leading doctrines of his civilisation, but in many fields he broke new ground and anticipated the findings of Western social scientists of the last two centuries. The passages have been grouped to illustrate Ibn Khaldun's views on: Historical Method; Geography; Economics; Public Finance; Population; Society and State; Religion and Politics; Knowledge and Society; The Theory of Being; The Theory of Knowledge. This translation is intended for students of thought, rather than specialised Arabic scholars, and for those interested in the intellectual background of the Arab world. First published in 1950 and reprinted several times, this revision contains a new chapter and a thoroughly revised and updated bibliography.