These divergences contributed not a little to the undermining of Anan's authority among the Karaites, and his faithful followers, the Ananites, were pushed to the wall; as their rigorous observances were entirely unsuited to ordinary life, they were finally obliged to emigrate to Jerusalem and adopt the hermit life of the old Essenes, as mourners for Zion. Gradually disappearing, they left the field free for the great noontide of Karaism in the tenth and eleventh centuries. The representatives of this epoch are: Abu Yusuf Ya'ḳub al-Ḳirḳisani, Sahl ibn Maẓliaḥ, Solomon ben Jeroham, Yafith ibn 'Ali, David al-Fasi, Abu al-Faraj Harun, Yusuf al-Baṣir and his pupil Abu al-Faraj Furḳan.
The first-named, Abu Yusuf Ya'ḳub al-Ḳirḳisani (called incorrectly by later authors and even by Steinschneider, "Yusuf" instead of "Abu Yusuf"), wrote in the third and fourth decades of the tenth century; he is a unique figure in Karaite literature on account of his historical sense, his comprehensive survey of the development of the Jewish sects, and his acute, even if partial, criticism of his predecessors. For the historical part of his work he consulted the works of David ibn Merwan al-Muḳammaṣ see Jew. Encyc. iv. 466, where he is confounded with a later David al-Muḳammaṣ) and the accounts of Mohammedanwriters, whose works, however, have not been handed down. Although a great admirer of Anan, whom he frequently defends, Ya'ḳub seldom agrees with him, and generally endeavors to mitigate the severity of the heresiarch's legal interpretations. Al-Ḳirḳisani went very far in regard to forbidden marriages, being one of the chief representatives of the so-called "system of extension" ("rikkub").
Al-Ḳirḳisani was, so far as is known, the first Karaite writer to defend the dictates of common sense and of knowledge in religious matters; the second part of his chief work, "Kitab al-Anwar" (Book of Lights), treats of the necessity of investigation and of reason, and of the determination of the proofs of reason and analogical conclusions. He adopts for Karaism without modification the views of the Motekallamin and the Motazilites. Since that time there has been a wide schism in Karaism between the followers of scientific investigation, who patterned their theology on the Mohammedan kalam and the Motazilite doctrines, and the Orthodox, who would have nothing to do with philosophy and science. Among the former are some Karaite scholars of the tenth century mentioned by their contemporary the Arabian polyhistor 'Ali al-Mas'udi, and Yusuf al-Baṣir, the foremost Karaite philosophical writer, together with his pupil Abu al-Faraj Furḳan (Jeshua b. Judah; about the middle of the eleventh century). Among the latter are the important Karaite authors Sahl ibn Maẓliaḥ, Solomon ben Jeroham, and Yafith ibn 'Ali, all three of whom lived during the middle and the end of the tenth century. The Karaites produced no original author in this field after the middle of the eleventh century, but merely translators from the Arabic, compilers, and imitators, such as Israel Maghrabi and his pupil Yafith ibn Saghir (13th cent.), Solomon Nasi (Abu al-Faḍl; 13th cent.), Samuel Maghrabi (14th cent.), and others.
The following Karaite writers of this epoch cultivating other fields are noteworthy: Exegetes: Al-Ḳirḳisani, Sahl ibn Maẓliaḥ, Solomon ben Jeroham, Yafith ibn 'Ali, and Yusuf ibn Nuḥ (10th cent.); Abu al-Faraj Harun, Abu al-Faraj Furḳan, and 'Ali ibn Sulaiman (11th cent.). Lexicographers: Abu Sulaiman Daud al-Fasi (end of the 10th cent.) and his editors Abu Sa'id (probably identical with Levi ha-Levi, beginning of the 11th cent.) and 'Ali ibn Sulaiman; the first-named knows nothing as yet of the triliteral roots of the Hebrew language, and the last-named hardly uses the new system, although acquainted with Ḥayyuj's works. As Hebrew grammarians, only the above-mentioned Yusuf ibn Nuḥ and Abu al-Faraj Harun (called "the grammarian of Jerusalem" by Ibn Ezra) need be noted; the latter wrote first his "Kitab al-Mushtamil," a comprehensive work in seven parts, which also includes a large part of Hebrew lexicography, and then made a compendium," Kitab al-Kafi," so that (1026) Ibn Ezra mentions eight works. Codifiers (of Karaite religious law): Ya'ḳub al-Ḳirḳisani, in the third and fourth decades of the tenth century, whose "Kitab al-Anwar" may be considered as the most important Karaite work written in the Arabic language; Sahl (called "Ben Zita" by Ibn Ezra), whose code was entitled "Sefer Dinim," although written in Arabic; Yafith ibn 'Ali, known only through citations, and his son Levi ha-Levi, one of the most noteworthy codifiers, who often agrees with the Rabbinites; Yusuf al-Baṣir, author of the "Kitab al-Istibṣar," of which the "Sefer ha-Abib" and "Sefer ha-Mo'adim," mentioned by Pinsker, are subdivisions; Abu al-Faraj Furḳan, Sahl ibn Faḍl Tustari (called in Hebrew "Yashar b. Ḥesed"; end of the 11th cent.), and others.
Although the Oriental Karaite authors since Nahawendi wrote in Hebrew with more or less fluency, there were no noteworthy poets among them. The orthodox and ascetic views of the earlier Karaites did not encourage secular poetry, which was held to profane the holy language; nor did they produce anything noteworthy in liturgical poetry ("piyyuṭim"), for according to Anan, with the exception of short benedictions, prayers could be taken only from the Psalter (see specimens in Harkavy, "Studien und Mittheilungen," viii.). Even in later times they generally either borrowed Rabbinite poems or resorted to imitations of them. The only Karaite poet who left secular poems, Moses Dar'i (13th cent.), either imitated or simply borrowed from the Judæo-Spanish poets. It goes without saying that polemics against Rabbinism were obligatory upon every Karaite author in the period of propaganda and extension. The writers mentioned herein attacked the Rabbinites on every occasion and in almost all their works, and also wrote special polemical pamphlets, as Solomon ben Jeroham against Saadia Gaon, Sahl and Yafith against Saadia's pupil Jacob b. Samuel, Yusuf al-Baṣir against Samuel ibn Ḥofni. Some Karaite writers may also be noted who are known only as polemicists, as Ibn Mashiaḥ and Ibn Sakawaihi; some details have recently been discovered regarding the latter's "Kitab al-Faḍa'iḥ" (Book of Infamies), which was refuted by Saadia.
In formulating the principles of primitive Karaism concerning the doctrine of the Law the leaders of the sect generally followed Mohammedan patterns. Anan, as has been seen, was influenced by Abu Ḥanifah, and added to the three sources of Islamic law—the Koran, the "sunnah" (tradition), and "ijma'" (the agreement of all Islam)—a fourth source, namely, "ra'y," i.e., speculation, or the speculative opinions of the teachers of the Law and of the judges, which are deduced by analogy ("ḳiyas"; Talmud, "heḳḳesh") from the laws originating in the other three sources. Anan, opposed on principle to Rabbinism, could not recognize tradition as a source of law, nor could he, the founder of a new sect, consider agreement as a basis for religious law; hence he found it all the more necessary to seize upon analogical speculation. But he introduced two important modifications, based on rabbinical precedent, into the principle of Abu Ḥanifah: (1) instead of logical analogy, of chief importance with Abu Ḥanifah, Anan gave preference to verbal analogy (the rabbinical "gezerah shawah"), and frequently even resorted to literal analogy; (2) for the religious laws which he based on his speculations he endeavored to deduce support from the Biblical text: he did not hesitate at the most forced interpretations, but followed rabbis who made deductions("asmakta") in support of ancient traditions. Hence this heresiarch believed himself justified in asserting that he took all his teachings directly from the Bible. Later, however, when Ananism with its opposition to traditional Judaism and its artificial system was gradually disappearing, and Karaism was so well established that it need hesitate no longer to call things by their right names, the Karaite leaders adopted openly the Mohammedan principles concerning canons of the Law. Thus Sahl ben Maẓliaḥ, according to Judah Hadassi, adopted outright Abu Ḥanifah's principles, with the single modification that instead of tradition he considered speculation and analogy as authoritative. Yusuf ibn Nuḥ entirely rejected speculation, like the non-Ḥanifitic Mohammedan theological schools; Levi ha-Levi (probably the reading in Hadassi should be "Abu Sa'id" instead of "Sa'id"), again, agrees with Abu Ḥanifah, though of course excluding tradition. Abu al-Faraj Furḳan similarly determines three categories of the Law, which agree with Abu Ḥanifah's categories, exclusive of tradition. However, many Mohammedan faḳihs also have excluded tradition from the socalled roots of the doctrine of the Law ("uṣul al-fiḳh"). Tradition was included among the nomocanons, under the curious designation "the inherited burden" ("sebel ha-yerushshah"), at a much later date, during the Byzantine epoch of Karaism.