Both the Khārijites and the Mu‘tazilite anarchists restated the libertarian aspect of the tribal tradition in Islamic form. With the Shī‘ites, by contrast, we encounter a thinking that can only be described as authoritarian. All Shī‘ites held the imam to be something more than an ordinary human being and explained his special status in terms of his kinship with the Prophet. Yet Shī‘ism also began among the conquerors, as has often been stressed, and the authoritarian style of thinking may well have tribal roots as well. For if the tribesmen of Arabia resisted kings, they also deferred to sanctity, as they showed when they accepted Muḥammad (and on many later occasions too). Early Shi‘ism boiled down to the claim that power should be handed to a man of sanctity, defined as somebody more closely related to the Prophet than the Qurashīs originally seen as constituting his family. A kinsman of the Prophet was bound to be rightly guided: it ran in the blood. It is an odd idea to a modern reader, but it made sense in medieval times, and not only to tribesmen. In a world in which social roles were overwhelmingly allocated on the basis of descent it seemed self-evident that humans were replicas of their forebears: children everywhere tended to step into their parents’ positions. The Shi‘ites thought that things had gone wrong because the Prophet's descendants had not been allowed to step into his.