Most evidently by these words is he shown to have fallen from heaven, who formerly was Lucifer, and who used to arise in the morning. For if, as some think, he was a nature of darkness, how is Lucifer said to have existed before? Or how could he arise in the morning, who had in himself nothing of the light? Nay, even the Saviour Himself teaches us, saying of the devil, Behold, I see Satan fallen from heaven like lightning. For at one time he was light. Moreover our Lord, who is the truth, compared the power of His own glorious advent to lightning, in the words, For as the lightning shines from the height of heaven even to its height again, so will the coming of the Son of man be. And notwithstanding He compares him to lightning, and says that he fell from heaven, that He might show by this that he had been at one time in heaven, and had had a place among the saints, and had enjoyed a share in that light in which all the saints participate, by which they are made angels of light, and by which the apostles are termed by the Lord the light of the world. (Book I, Chapter 5, Part 5)

I am not yet sure where Origen may be heading, but if it is a rejection of dualism, I will join him.

Good is innate in all of creation. The Good includes freedom. The exercise of freedom can result in error. Error is the origin of evil.

This formula can, I think, be defended by observation and scripture. Let's see if that is what Origen undertakes.