Judaism is the "religion, philosophy, and way of life" of the Jewish people. Originating in the Hebrew Bible (also known as the Tanakh) and explored in later texts such as the Talmud, it is considered by Jews to be the expression of the covenantal relationship God developed with the Children of Israel. According to traditional Rabbinic Judaism, God revealed his laws and commandments to Moses on Mount Sinai in the form of both the Written and Oral Torah. This was historically challenged by the Karaites, a movement that flourished in the medieval period, retains several thousand followers today and maintains that only the Written Torah was revealed. In modern times, liberal movements such as Humanistic Judaism may be nontheistic.