The durable unit of Arab-Islamic society was the city with its market, mosque, and schools, which preserved a shared high culture of law and learning even as dynasties rose and fell above it. Political power was often unstable and foreign, but the urban religious and legal elite (the ulama) provided continuity that outlasted any particular ruler.
A ruler in Islamic political thought was accepted not because he embodied the community's will but because he maintained the conditions under which the revealed law could be obeyed: public order, justice, and defense of the faith. Authority was thus justified instrumentally, as a necessary guardian of religious life, rather than as an end in itself, which left even strong rulers dependent on the approval of religious scholars.
The 14th-century thinker Ibn Khaldun explained political history through asabiyya, the group solidarity that lets desert or tribal peoples conquer settled cities; once in power the dynasty grows luxurious, its solidarity erodes over roughly three generations, and a new cohesive group from the margins overthrows it. Hourani presents this as both a theory and an observed pattern across the successive dynasties of North Africa and the Middle East.
From the 19th century, Arab intellectual and political life is read as a series of attempts to answer the shock of European power: whether to borrow its techniques, revive an idealized early Islam, or forge secular nationalism. Reform movements, Islamic revival, and Arab nationalism appear less as independent developments than as competing strategies for recovering strength in a world Europe had come to dominate.