Why was the Muslim community beset by divisions even though the Qur'an had been preserved exactly as revealed?  This episode examines the emergence of the second, and most controversial source of Islamic law: the Hadith, or sayings of the Prophet Muhammad.  In the early centuries of Islam, over half a million reported sayings circulated, with most experts accepting no more than 2% as accurate.  Competing the hadith would become the basis of controversies over law and practice, and the science of Hadith analysis became one of the most important intellectual and legal disciplines of the Muslim empire, and remains so today.