It is not possible here to give an account of the richness of this book which in relation to many controversial points of Islamic history before the Mongol conquest (the well guided Caliphs, the Abbasid revolution, the birth of Sunnism etc.) proposes stimulating new readings and rectifications of the current common interpretation. One may observe by way of an example that Crone, not confining herself to the by now usual cry of pain at the translation of jihad by 'holy war', presents an analysis of the phenomenon which diverges both from apologetics and from gratuitous polemic.
The fundamental thesis of the book is that the early Islamic community, marked by the complete fusion of religion, government and society, represented an exceptional archaic reality within the Medieval panorama of the seventh century which can be explained solely with reference to the tribal context in which Muhammad operated. In order to find in the whole of the history of the Middle East an analogy with the Muslim community of Medina it is necessary to go back 1,800 years to Moses and the tribes of Israel.
This unusual point of departure determined the special physiognomy of Muslim political thought which was forced to come to terms with the archaic ideal of the 'multipurpose polity', to employ a phrase that recurs throughout the book, in a context that was made daily more complex by the military campaigns, whilst the Arab tradition of the conquerors was fusing with the traditions of the conquered peoples first of all the Persians. Crone illustrates the progressive separation of the spheres of government and of religion, a phenomenon well attested to by the sources but still not well known to a wider public, and in a second part, entitled 'Government and Society', the author expounds her theory about the origins of power and inequality, the expectations of society as regards its governors, and the ideal beliefs that animated political action. In this Crone presents a very much alive picture, and one that is to a great extent unprecedented, of the classical Muslim world.
The guiding idea of the book, namely the progressive differentiation of the polyvalent political community of early Islam, is summarised in the conclusion through the employment of the image of three circles: religion, government and society. At the beginning of Islam the three circles coincided. Subsequently, the first two circles gradually drew apart until at the end of the period under analysis (1258), with the disappearance of the caliphate, there was a net division between religion and government but still the almost complete overlapping of religion and society.
During the successive period the circle of society would no longer totally overlay the circle of religion, whilst the importance of the state grew. Today, the author concludes, the options available are two in number: to continue along the path of a privatisation of religion and a complete separation of the three circles or to restore as much as possible their overlapping. Even if the belief that religion can exist in a modern society solely as a private fact is certainly reductive, a reading of this book, which does not assume any prior knowledge of Islamic history, is to be recommended to anyone who wishes to have a better understanding of certain fundamental co-ordinates by which to locate the contemporary debate within the Muslim world.