Orthodox Jews are those who accept the authority of Orthodox rabbis in the interpretation of Jewish law, based on the 613 commandments in the Torah. Observing Jewish law to Orthodox standards does not require isolation from the secular world nor does it require rejection of all aspects of modern culture. The Modern Orthodox branch of Orthodoxy encourages higher education and engagement with the modern world. Hassidic Jews are sometimes described as ultra-Orthodox, but this is a misnomer. Rather, the Hassidic movement is a pietist movement with deep connections to Kabbalah and mysticism and they have no interest in developments that led to the development of non-Orthodox Judaism in the 19th and 20th centuries. Each Hassidic sect revolves around its rebbi, that is, chief rabbi. In some sects