Although Islamicate patterns are not explicit and their very existence has yet to be established, their impact on the political conduct of Muslim peoples may be even greater than Islamic ones. Islamic influences affect only persons seeking to live by the law; Islamicate influences affect all Muslims. The Shari'a, especially in modern times, inspires only a portion of the umma and it covers only some aspects of public life (saying nothing, for instance, about the way a ruler should be selected); Islamicate influences affect the Weltanschauung of everyone in Islamdom, including even the dhimmis. Between the two, Islamic and Islamicate influences shaped Muslim political culture and constitute the legacy of Islam. These are also the forces that continue to make Islam important today. However much institutions, attitudes, and customs have changed, the Muslim approach to politics derives from the invariant premises of the religion and from fundamental themes established more than a millennium ago.