Karaism, founded in the Middle East around the 9th century CE, is a Jewish sect that rejects the authority of the Talmud and the rabbinic claim of an “Oral Torah” that can be traced back to Moses’ revelation at Sinai. While Karaites have their own distinctive laws and practices, and have maintained separate Jewish communities in Egypt, Eastern Europe, Crimea, and elsewhere, for most of their history they have also regularly interacted with “Rabbanites,” as they call non-Karaite communities. The Ukrainian-born scholar Simḥah Isaac Lutski (1716-1760) represented one of the high points of Karaite intellectual life, as Daniel Lasker writes:
Lutski, a scion of a long line of Karaite adepts, . . . could trace his lineage back through seven generations and over 150 years. He was an expert in Karaite literature, providing extensive bibliographical lists in two of his  books. He wrote treatises devoted to specific Karaite subjects, such as the calendar, and commentaries on classical Karaite literary works. Yet at the same time he was also very familiar with Rabbanite literature, citing among others Isaac Abravanel, Levi Gersonides, Solomon ibn Gabirol, Judah Halevi, and Profiat Duran. . . . Lutski was also not averse to citing non-Jewish sources, both Greek and Roman philosophers (including Plato, Aristotle, and Seneca) and Arab authorities (including al-Ghazali and al-Tabrizi). . . .
Lutski . . . knew about modern science, with its heliocentric world and atomic theory, but rejected it as speculative; and he was light-years away from the Berlin [Jewish] Enlightenment. Despite living in the mid-18th century, Lutski was, in many senses, a quintessential medieval Jew in terms of his religious outlook. In one of his earliest books, Lutski attempts to prove the creation of the world and the existence, incorporeality, and unity of God. He does so by using an eclectic collection of 42 propositions, all well-attested in medieval physics and metaphysics. . . . This is the world of Aristotle and Ptolemy, not Copernicus, Galileo, and Newton. . . .
[But] it is in the field of Kabbalah that Lutski made his most distinctive contribution to Karaite thought. Kabbalah had not been shunned by Karaites completely before Lutski, but it was generally far from their worldview. Early Karaites attacked Rabbanites for the non-rational aspects of rabbinic Judaism. . . . Yet, as Karaites became closer to Rabbanites [after the 15th century], and as Kabbalah became dominant among the latter, some Karaites were attracted to mystical ideas as well. . . .
What is most remarkable is Lutski’s claim that the Kabbalah was given by God to Moses on Mount Sinai as part of divine revelation and transmitted orally from generation to generation (thus the name “Kabbalah,” [meaning] tradition). Lutski, the Karaite, was not ready to accept a Sinaitic legal Oral Torah that complemented the laws of the Written Torah, but he did believe in an oral mystical tradition. According to Lutski, if it had not been for the vicissitudes of Jewish life over the centuries, the Jewish people would not have lost this reliable tradition and it would not have become restricted to a select few. The non-kabbalists among both the Karaites and Rabbanites were not to be blamed for their ignorance of this divine wisdom.
Read more on Tablet: http://www.tabletmag.com/jewish-arts-and-culture/227441/karaite-rabbi-lutski-eastern-europe