From an interview:
“In college I was given Plato to read and thereupon became aware of the possible existence of a metaphysical realm beyond or above the sensory world. I came to understand that the human mind could conceive of a realm of which the empirical world was epiphenominal. Finally, I came to believe that in a certain sense the empirical world was not truly real, at least not as real as the archetypal realm beyond it. At this point I despaired of the veracity of sense-data. Hence in novel after novel that I write I question the reality of the world that the characters’ percept-systems report. Ultimately I became an acosmic pantheist, led to this point of view by decades of skepticism.”
Weird Studies Podcast episode on his uncompleted Owl in the Daylight also describes a type of short story which was a reveiw of a book that didn’t exist as “holographic” in that it “projects” a text larger than the actual text of the story.