Johannes Scotus Eriugena
Weinstein examines the philosophy of 9th century theologian Johannes Scotus Eriugena, who proposed that "God has created the world out of his own being", and identifies this as a form of pandeism, noting in particular that Eriugena's vision of God was one which does not know what it is, and learns this through the process of existing as its creation. In his great work, "De divisione naturae" (also called "Periphyseon", probably completed around 867 AD), Eriugena proposed that the nature of the universe is divisible into four distinct classes: