Eriugena (815 – 877 CE) was Irish and was called to the French court of Charles the Bald to translate Plato and Dionysius. He merged the work of Augustine and Dionysius, working them together with many other authors, to create a dialectical system of kataphania and apophania. The first European Christian Platonist, Hegel wrote about him in his History of Philosophy, “With him, true philosophy first begins”, tracing the evolution of philosophy up to himself. I wrote about the similarities of Eriugena and Hegel for my master’s thesis. Eriugena was one of the only people in Europe who could read Greek at the time, and so he was protected in the court of Charles from the Pope, who charged him with heresy and pantheism, in exchange for translating and commentary. Augustine was cannon for the Church, and Eriugena argued that the ecstatic unknowing of Dionysius and Augustine are two sides of the same coin.
Eriugena saw the One as Hyper-Ousia, Super-Being, the sum of all being and non-being, the source of both but neither of the two at the same time. He took the radical unknown One of Dionysius and made it the unknown source of both known and unknown in all levels of the cosmos. For Eriugena, psychology is physics, as we co-create our world as a product of our vision and the One’s vision. The One is unknown to itself and fully known to itself above human divisions of judgement, and it shares both of these with human beings, the special mediators of the cosmos. Like in Sufism, Humans are unique in potentially being God, encompassing the lowest and highest of all orders (which Eriugena refers to as the worm and the angel). He also, like some Muslim philosophers, argued that authority comes from reason, not the other way around.