** For those readers who would insist upon viewing Dick as a "mad" charlatan tossing about ideas he could not comprehend as truly as might a "sane" and reasonable scholar, the following case study -- in miniature -- may prove illuminating.
The late Ioan P. Couliano, an acclaimed historian of religious thought who taught at the University of Chicago Divinity School and worked as a scholarly collaborator with the eminent Mircea Eliade, had occasion to examine one novel of the "Valis Trilogy" -- The Divine Invasion -- in his landmark survey of Gnostic thought The Tree of Gnosis (New York: HarperCollins, 1992). Couliano's judgment of the thematic influences in that novel was intended to rebut those who, in Couliano's view, too carelessly cited Dick as an example of a "Gnostic" science fiction writer:
"A closer look at the novel shows that, indeed, Dick took inspiration from Jewish and Jewish-Christian apocalyptic literature (especially The Vision of Isaiah), yet his novel, which describes the descent of God to the earth through the first heaven controlled by the troops of Belial the Opponent, and God's encounter with his wisdom in a kindergarten, makes no use of gnostic material."
Now compare this with an analysis by Dick himself, written in 1979, in the concluding pages of an unpublished outline of the novel in progress (then titled Valis Regained) that would become The Divine Invasion. Note that Dick himself recognizes the absence of a fundamental Gnostic good-evil dualism in this novel. He also makes reference to Isaiah (though his source is the Bible, not the apocalyptic text cited by Couliano):