Usooli and AkhbariShiaTwelverMuslims believe that the study of Islamicliterature is a continual process, and is necessary for identifying all of God's laws. Twelver Shia Muslims believe that the process of finding God's laws from the available Islamic literature will facilitate in dealing with any circumstance. They believe that they can interpret the Qur'an and the Twelver Shi'a traditions with the same authority as their predecessors. This process of ijtihad has provided a means to deal with current issues from an islamic perspective. Generally, the Twelver Shi'a clergy have exerted much more authority in the Twelver Shi'a community than have the Sunni ulema.
Most Sunni scholars, preachers, and judges (collectively known as the Sunni ulema) traditionally believe that the door of ijtihad, or private judgment, closed some four hundred years after the death of Muhammad. Sunni Muslims consider that Sunni scholars had studied the Qur'an and hadith for centuries, during which time they developed the four schools of law (madhhab), and that the height of Islamic knowledge was reached at this time, thus these teachings should be given the highest regard. However, this more expresses the status quo of the Sunni way of thinking than what Sunni ulema really believe. In other words Sunni scholars believe that categorically ijtihad is still possible, but they also believe that doing ijtihad can add very little to what is there given the effort of the older generations of scholars.