text: Sunni\nThe Sunni are the largest group in Islam. In Arabic, as-Sunnah literally means "principle" or "path." Sunnis and Shi'a believe that Muhammad is a perfect example to follow, and that they must imitate the words and acts of Muhammad as accurately as possible. Because of this reason, the sunnah (practices which Muhammad established in the community) is described as a main pillar of Sunni doctrine, with the place of hadith having been argued by scholars as part of the sunnah.\n\nSunnis recognize four major legal traditions (madhhabs): Maliki, Shafi'i, Hanafi, and Hanbali. All four accept the validity of the others and a Muslim might choose any one that he/she finds agreeable to his/her ideas. There are also several orthodox theological or philosophical traditions (kalam).\n\n\nShi'a\nShi'a Muslims, the second-largest branch, differ from the Sunni in rejecting the authority of the first three caliphs. They honor different accounts of Muhammad (hadith) and have their own legal traditions. The concept of Imamah (leadership) plays a central role in Shi'a doctrine. Shi'a Muslims hold that leadership should not be passed down through a system such as the caliphate, but rather, descendants of Muhammad should be given this right as Imams.