288 A History of Judaism
serious threat posed by Karaism, which set itself in direct opposition to
the rabbis. The Babylonian gaon Saadiah, who played a major role in
the tenth century in stemming Karaism in the east, also wrote for the
benefit of his rabbinic flock a deeply polemical treatise against the ‘two
hundred critical comments on the Bible’ that had been composed in
Persia in the ninth century by a certain Hiwi al- Balkhi. Al- Balkhi’s
polemic, drawing on sceptical comments from many earlier sources
(some of them Christian and some of them dualist), attacked the Bible
in ways that were abhorrent to Karaites and rabbis alike.^32
The legacy of the religious system crafted by the rabbinic schools over
the thousand years after 70 ce has been fundamental to most later
forms of Judaism, with the production by the end of the first millen-
nium of a definitive biblical text by the masoretes and the establishment
of formalized prayer in fixed forms encapsulated in the liturgical works
of the geonim, especially Amram and Saadiah. Above all, the Mishnah
and Talmuds (and especially the Babylonian Talmud) became the base
texts for the development of rabbinic law from the sixth century to the
present. Rabbinic forms of study, in educational institutions which
matured from small study groups to large academies, spread out from
insignificant beginnings in Yavneh to encompass Babylonia to the east
and Spain to the west.
As a result, by 1000 ce much of the Jewish world was touched by the
rabbis. But some forms of Judaism developed in quite different direc-
tions during the first millennium ce, and these will be the subjects of the
next chapter.