As a fan, it's clear to me that this season the show has decided to become less like a Robinson Crusoe type castaway tale, and more like a PKD novel.
There is a glut of blogs out there that dissect and parse each episode, looking for additional clues. I don't have the energy or motivation for anything so detailed (in fact it's been a couple years since I read VALIS) so instead, here are some elements from VALIS and PKD's non-fiction that I think are relevant:
While last week's (absolutely brilliant) episode seemed much more like Vonnegut's Slaughterhouse Five with Desmond becoming unstuck in time (like Billy Pilgrim), the episode also resonated with some of the themes in VALIS. In VALIS, the protagonist, Horeselover Fat, becomes convinced a consciousness from another time period has become enmeshed in his own mind. Fat feels very strongly a Roman from the first century is coexisting with him in his consciousness.
So that's one potential connection - we'll discover in coming weeks if this theme from the book is the reason for the allusion. Having given this a lot of thought, I've decided that I think the far more relevant aspect of the book is the novel's exploration of ontology.
PKD quotes Heraclitus in VALIS as saying "Reality is in the habit of concealing itself."
Sounds like a tag line for the show doesn't it?
Here's a relevant passage from Dick's 1978 essay "How To Build A World That Doesn't Fall Apart Two Days Later":
"Well, as I said earlier, an author of a work supposed fiction might write the truth and not know it. To quote Xenophanes, another pre-Socratic: "Even if a man should chance to speak the most complete truth, yet he himself does not know it; all things are wrapped in appearances" (Fragment 34). And Heraclitus added to this: "The nature of things is in the habit of concealing itself" (Fragment 54). W. S. Gilbert, of Gilbert and Sullivan, put it: "Things are seldom what they seem; skim milk masquerades as cream." The point of all that is that we cannot trust our senses and probably not even our a priori reasoning. As to our senses, I understand that people who have been blind from birth and are suddenly given sight are amazed to discover that objects appear to get smaller and smaller as they get farther away. Logically, there is no reason for this. We, of course, have come to accept this, because we are use to it. We see objects get smaller, but we know that in actuality they remain the same size. So even the common everyday pragmatic person utilizes a certain amount of sophisticated discounting of what his eyes and ears tell him.
Little of what Heraclitus wrote has survived, and what we do have is obscure, but Fragment 54 is lucid and important: "Latent structure is master of obvious structure." This means that Heraclitus believed that a veil lay over the true landscape. He also may have suspected that time was somehow not what it seemed, because in Fragment 52 he said: "Time is a child at play, playing draughts; a child's is the kingdom." This is indeed cryptic. But he also said, in Fragment 18: "If one does not expect it, one will not find out the unexpected; it is not to be tracked down and no path leads us to it." Edward Hussey, in his scholarly book The Pre-Socratics, says:
If Heraclitus is to be so insistent on the lack of understanding shown by most men, it would seem only reasonable that he should offer further instructions for penetrating to the truth. The talk of riddle-guessing suggests that some kind of revelation, beyond human control, is necessary... The true wisdom, as has been seen, is closely associated with God, which suggests further that in advancing wisdom a man becomes like, or a part of, God."
This passage from VALIS also seems relevant:
"As to our reality being a projected framework -- it appears to be a projection by an artifact, a computerlike teaching machine that guides, programs, and generally controls us as we act without awareness of it within our projected world. The artifact, which I call Zebra, has "created" (actually only projected) our reality as a sort of mirror or image of its maker, so that the maker can obtain thereby an objective standpoint to comprehend its own self. In other words, the maker (called by Jakob Bohme in 1616 the Urgrund) is motivated to seek an instrument for self-awareness, self-knowledge, an objective opinion or appraisal and comprehension of the nature of itself (it is a vast living organism, intrinsically -- without this mirror -- without qualities or aspects, which is why it needs the empirical world as a reflection by which to "see" itself)."
Yes, the name Jakob (cue eerie-sounding theremin music)!
Here's a detail that may be relevant: Locke is reading the Vintage edition of VALIS which I believe was released in the early 1990s, which is a bit later than most of the stuff on the island seems to date from (notice Ben's top loading VCR in last night's episode, those went out of style in the 80s. Perhaps this is unintentional, but what if it isn't!