Contrary to the available translations, the author proposes or suggests translating the concept of ‘umran into ‘urbanisation’ and hadara into ‘civilisation’. This issue of translation is essential, since ‘ilm al-‘umran is the foundation of the intellectual edifice or structure of Ibn Khaldun. When searching the deep reasons or causes of the crisis which the Maghreb of the fourteenth century undergo, Ibn Khaldun has uncorked a general conception of society and its evolvement as a whole. This evolvement is submissive to a universal determinism which is that of ‘umran al-’alam, ‘universal urbanisation’. The genius of Ibn Khaldun is inexhaustible; we can appreciate it only when we approach it from different perspectives, after we have restored and re-established his unity and his deep harmony. It is not enough for us to understand this conception of the world; we must also live within its framework as well as apply it to our times. It is only thus Ibn Khaldun's work can reveal its full meaning.