The previously underground Gnostic movement has experienced a resurgence in recent years, and much of the renewed interest is attributable to Philip K Dick. Dick was a self-proclaimed Gnostic, and strands of Gnostic thought can be found throughout his writings, most notably VALIS.
The website www.phildickiangnosticism.com explores, as its name suggests, the Dick's gnosticism in detail, although the author of the site admits that it can be very hard to define. This arises in no small part from the fact tthat much of Dick's beliefs were expressed obliquely, through his fiction.
An audio lecture about the Gnosticism of Philip K Dick is available at the Gnostic society
The i ching
Dick was a believer in the i ching system of fortune telling. However, later in life he decided that the i ching was a malevolent force that would lead him down false paths.
The i ching appears in The Man in The High Castle as a device that reveals hidden truths. Dick reportedly used the i ching to help him write the book itself.
A pervasive theme in Dick's work is the question of the existence, and nature of, external reality. Am I human? Am I real? Are my memories real, or am I merely a robot with pre-programmed memories? Are my perceptions of the outside world trustworthy?
These are all questions that philosophers have grappled with. Dick brought many of these questions to life with stories that often act as vivid thought experiments in the nature of external reality.
Philip K Dick's work is replete with paradoxes, contradictions, catch-22's and similar constructs that invariably lock the characters into situations where they must face their fundamental human limitations, and their mortality.
What does it mean to be human?
Time and again we encounter variations of the question "what is human?" in Dick's work. Androids appear to be people. People wonder if they are androids. It is worth noting that he seemed to have no faith in the so-called Turing test of human intelligence. In his worlds, robots are as intelligent, or more so than humans. Dick devised an alternative test to tell them apart: the Voight-Kampff test, which relied not on intelligence, but on empathy.