doctrinally the mystics become the negative counterpart of the nominalists
based in the most insulated academic faculty of the universities.
The most influential mystics established their own lines of organization.
Jan van Ruysbroeck, a preacher without formal training in theology, and of
imperfect Latin, was influenced by Eckhart’s writings and established a devo-
tional community in Holland in 1343. His colleague Gerard Groote later in
the century organized the Brethren of the Common Life. Although its raison
d’être was devotions, it became a house of studies turning out some famous
pupils: Thomas à Kempis, whose Imitation of Christ, circulated from 1422 by
the copyists of the Brethren, was the most popular devotional book of the
period; then in successive generations a series of notable scholars, including
Cusanus, the nominalist systematizer Biel (300 in the key to Figure 9.7), and
Erasmus. The period was also rich in practicing mystics of a non-intellectual
type (e.g., 168, 184a, 269, 270, 288); some of these became saints through
their devotions, from Saint Catherine of Siena (229), down through the ascetic
reformer Saint Teresa of Avila and her circle in the late 1500s.
Notice a parallel in Islamic intellectual life. After the creative philosophical
networks disintegrated (after al-Ghazali in the east, Ibn Rushd in Spain),
activity was increasingly dominated by Sufi mystics. Ibn ÀArabi, who emerged
directly from Ibn Rushd’s orbit, was the most systematic combination of
mysticism and philosophy, a parallel to Eckhart at the point of transition. There
is an organizational reason for this parallel development: mysticism thrives on
decentralization. Jewish philosophy provides a confirming instance.
The networks of Jewish rationalistic philosophy in Spain had peaked during
their overlap with Islamic and Christian networks. In the late 1100s this
cosmopolitan network broke up as the political situation polarized between
the fundamentalist Almohad invasion from North Africa, then the Christian
reconquest. Religious particularism and intolerance intensified. Jewish cosmo-
politans migrated north and were absorbed into the movements of their Chris-
tian counterparts. Within the Talmudic academies, Maimonides’s Aristotelean-
ism was repudiated in favor of defending the distinctness of Judaism against
Christianity. Doctrines were revived from the period of Jewish Gnosticism,
interpreting traditional texts as esoteric symbols of cosmic correspondences
and prophecies (Scholem, 1946, 1990). In Provence and Catalonia, spanning
the Pyrenees, regions of the Catharist movement and Christian heresy-hunting,
a network of rabbinical scholars in the late 1100s began to produce Kabbalist
texts. These were successors to the network propagated most widely in Spain,
a region of growing religious persecution. The Neoplatonism of the cosmo-
politan trans-religious period gave way to an esoteric defense of Judaism. In
the late 1200s the most popular texts of the Kabbalah appeared, interpreting
prophecy as a mystical union with God, and teaching breathing techniques to496 •^ Intellectual Communities: Western Paths