Hippolytus of Rome, The Refutation of All Heresies VI.28: The Valentinian Origin of the Creation

As, therefore, the primary and greatest power of the animal essence came into existence, an image (of the only begotten Son); so also the devil, who is the ruler of this world, constitutes the power of the material essence, as Beelzebub is of the essence of demons which emanates from anxiety. (In consequence of this,) Sophia from above exerted her energy from the Ogdoad to the Hebdomad. For the Demiurge, they say, knows nothing at all, but is, according to them, devoid of understanding, and silly, and is not conscious of what he is doing or working at. But in him, while thus in a state of ignorance that even he is producing, Sophia wrought all sorts of energy, and infused vigour (into him). And (although Sophia) was really the operating cause, he himself imagines that he evolves the creation of the world out of himself: whence he commenced, saying, “I am God, and beside me there is no other.”