The ideology of the Iranian Revolution has been called a "complex combination" of Pan-Islamism, political populism, and Shia Islamic "religious radicalism". The Iranian revolution expresses itself in the language of Islam, that is to say, as a democratic movement with a religious leadership, a religiously formulated critique of the old order, and religiously expressed plans for the new. Muslim revolutionaries look to the birth of Islam as their model, and see themselves as engaged in a struggle against paganism, oppression, and empire. — Bernard Lewis, Islamic Revolution