William Sarill has made a cool discovery about Dick's mis-use of Greek. If that name sounds familiar to you it's probably because Phil Dick acknowledges at the beginning of his 1970 novel, Maze of Death, that the book grew out of late night sessions undertaken with him "to develop an abstract, logical system of religious thought, based on the arbitrary postulate that God exists."
Dick uses the Greek word δοκός (dokos) to mean illusion obscuring the true reality. The Glossary in the Exegesis defines dokos as deception, the lack of true perception, a cognate for maya.
I've always been bothered by this. Dokos in Greek (and specifically in the New Testament) refers to a piece of timber used as the main beam of a house; cf. Matt. 7:3-5 and Luke 6:41-42 in the KJV, "the mote in thy brother's eye" vs. "the beam [dokos] in thine own eye." What was PKD actually thinking of? It had nothing to do with houses or passing judgments on others.
I found the answer of all places in a text by Henry Corbin, Cyclical Time and Ismaili Gnosis. Corbin was a French theologian and scholar of Islamic mysticism. His work was primarily focused on Iranian Islam, which he believed had esoteric roots in older elements related to Platonism and Zoroastrianism. I'd known of his work before but hadn't attempted to engage with it until I began researching cyclical time in various esoteric traditions. (Dick said that orthogonal time was periodic, which prompted my investigation.)
The correct term PKD was looking for was δόκησις (dokesis), not dokos. It's derived from δοκεῖν (dokein), meaning to seem, and is not etymologically related to dokos. Dokesis means phantasm or appearance in the sense of apparitional reality, according to Corbin. It's also the root word of Docetism, the heresy proclaiming that Jesus only seemed to be human and his human form was an illusion. (Thus, the wounds/stigmata he suffered on the cross were "only apparently real".) The church declared this a heresy because it denied the full humanity of Jesus.
Corbin also mentions a current definition of dokesis as "simulacrum". How perfectly Dickian is that?? In fact there are other paragraphs in Corbin's book that are directly related to themes in the Exegesis, which makes me wonder about PKD's sources. There are no mentions of Corbin in the Exegesis, but since he was a member of Jung's Eranos group it's possible that Dick encountered some of his ideas before.
The other thing I'm left wondering about is how the religious scholars who edited the Exegesis managed to overlook Dick's confusion of dokos with dokesis.