One reference I have sometimes wondered about, as I once wrote elsewhere, was whether Dick had read or encountered the work of Heidegger. (Tessa Dick, his former wife, wrote to me several years ago noting that “one of Phil’s favorite topics was Heidegger’s concept of Ereignis, that is, that existence creates or gives birth to space and time. I guess you could say that Phil’s writing focuses on phenomenology.”)
This can now be confirmed. The sixth and final volume of his Letters has at last appeared (the other five appeared nearly 20 years ago but this one was delayed) begins almost immediately with this letter to John B. Ross:
[January 30, 1980]. As I read your letter I thought about the philosophy of Martin Heidegger and wondered if you’d read him.I just read him recently and his ideas made quite an impression on me. It seems as if both you and I have been fighting for what he calls authentic existence,which always involves a crisis as the person becomes aware of the possibility of his own nonexistence. This sets off primal dread but it can lead to authentic existence, finally.
PKD may have been interested in Heidegger (and philosophy, specifically german idealism), yet I am not sure we should agree to the widow Dick's (Tessa's a nice person, really...being screwed by publishing and entertainment biz) assessment of PKD as primarily occupied with "phenomenology."
In his fiction PKD did offer speculations on the possibility of...transcendence or mysticism of a sort (probably triggered by his readings of quantum physics), and may allude to Noumena here and there (as with UBIK, a sort of deistic Intelligence), but....I would hesitate to call it a contemplation of Being, or traditional theology. (In his later years, he ...referred to one of his religious concepts as...ZEBRA--and suggested a certain gnostic element...).
At times PKD overdid the mysticism, IMHO. One of the interesting aspects of A Scanner Darkly was PKD's ...return to a somewhat darker, realistic mode. Postmodernism's not really my cup of tea, but it seems a bit...Baudrillardian--and like any good sci-fi scribe PKD addresses simulacra of a sort throughout his writing (tho' one man's simulacra is another's hallucination, perhaps...)-- ASD also had a political edge, as in...the politics of cops and robbers, tho' updated for hippies.