Urth of the New Sun (kabalistic references)SF-Lovers

I enjoyed "The Urth of the New Sun", though I don't think it reaches quite the heights of the previous series. It definitely has my vote for the best overtly Christian science fiction novel. One thing (actually many things, but let's pretend) confused me: Why the garbled kabala? He repeatedly referred to Urth's universe as Briah, which is the world of creation in the four worlds model - just one short of Atziluth, the abode of God. In orthodox kabala, our universe is Assiah, two steps below Briah. Then he confused me further by going from Briah to Yesod, with Yesod utterly enveloping and transcending Briah. This would make sense if he said "Malkuth" for "Briah", or even "Assiah", since in the four planes model of the Tree Assiah and Malkuth are analogous; but Yesod is generally considered a lower sphere than the Briatic spheres. Was Gene just confused, or was he trying to say something in his obscure way? Any ideas from other students of kabala who have read "The Urth of the New Sun"? Is this just yet more (sigh) goyim kabala? Tim Maroney