and it is generally accepted that early Islamic jurisprudence developed out of a combination of administrative and popular practices shaped by the religious and ethical precepts of Islam. It continued some aspects of pre-Islamic laws and customs of the lands that fell under Muslim rule in the aftermath of the early conquests and modified other aspects, aiming to meet the practical need of establishing Islamic norms of behavior and adjudicating disputes arising in the early Muslim communities. Juristic thought gradually developed in study circles, where independent scholars met to learn from a local master and discuss religious topics. At first, these circles were fluid in their membership, but with time distinct regional legal schools crystallized around shared sets of methodological principles. As the boundaries of the schools became clearly delineated, the authority of their doctrinal tenets came to be vested in a master jurist from earlier times, who was henceforth identified as the school's founder. In the course of the first three centuries of Islam, all legal schools came to accept the broad outlines of classical legal theory, according to which Islamic law had to be firmly rooted in the Quran and hadith.