According to the Jewish tradition, the oral law was given to Moses on Mount Sinai together with the written law. During the period of the Second Temple, the oral law was upheld by the Pharisees in opposition to the Sadducees. Eventually it was studied in the academies, and was written down in the Mishnah which was compiled by Judah Ha-Nasi in the second century. After centuries of discussion, the oral law was recorded in the Talmud. After the redaction of the Talmud in the sixth century, it was further studied in talmudic academies. In the gaonic period, the Karaites rejected the authority of the oral law. Modern non-Orthodox Judaism rejects the belief that the oral law was revealed to Moses on Mount Sinai; instead it is viewed as originating through discussion and interpretation over the centuries.