Alireza Doostdar at the University of Chicago Divinity School website:
The group known as the Islamic State in Iraq and the Levant or simply the Islamic State (ISIL, ISIS, or IS) has attracted much attention in the past few months with its dramatic military gains in Syria and Iraq and with the recent U.S. decision to wage war against it.
As analysts are called to explain ISIS’ ambitions, its appeal, and its brutality, they often turn to an examination of what they consider to be its religious worldview—a combination of cosmological doctrines, eschatological beliefs, and civilizational notions—usually thought to be rooted in Salafi Islam.
The Salafi tradition is a modern reformist movement critical of what it considers to be misguided accretions to Islam—such as grave visitations, saint veneration, and dreaming practices. It calls for abolishing these and returning to the ways of the original followers of Prophet Muhammad, the “salaf” or predecessors. Critics of Salafism accuse its followers of “literalism,” “puritanism,” or of practicing a “harsh” or “rigid” form of Islam, but none of these terms is particularly accurate, especially given the diverse range of Salafi views and the different ways in which people adhere to them [1].
Salafism entered American consciousness after September 11, 2001, as Al-Qaeda leaders claim to follow this school. Ever since, it has become commonplace to demonize Salafism as the primary cause of Muslim violence, even though most Salafi Muslims show no enthusiasm for jihad and often eschew political involvement [2], and even though many Muslims who do engage in armed struggles are not Salafi.
ISIS is only the most recent group whose behavior is explained in terms of Salafism.
More here.