John Scotus Erigena, 810–877?

John Scotus Erigena was an Irish theologian, translator, and commentator who sought to integrate Greek and Neoplatonist philosophy with Christian belief.  His writings are based largely on the transcendentalist standpoint of Neoplatonism as found in Pseudo-Dionysius and the Greek Fathers.  Erigena’s principal work, De divisione naturæ (862–866), was an attempt to reconcile the Neoplatonist doctrine of emanation with the Christian tenet of creation.  The work was especially influential among the Western mystics and the thirteenth-century Scholastics, despite (or perhaps because of) its pantheistic implications.
Erigena’s writings are notable for their bold and free manner of expression, penned at a time when most writers practiced self-censorship out of deference to orthodox theology.  His emphasis on knowing God through direct revelatory experience, rather than through the oppressive dogmas of Church orthodoxy, foreshadowed the same posture in Giordano Bruno, as well as the later idealism of George Berkeley and the German transcendental philosophers.