Philip K. Dick is one of the more influential American writers of the last century. The author of more than 40 novels and dozens of short stories, his work has been adapted into several major motion pictures, including Blade Runner, Total Recall, and Minority Report.

This week brings a new book, The Exegesis of Philip K. Dick, that collects notes, journal entries, letters, and sketches concerning a visionary experience he had in 1974.

In the excerpt below, Dick writes that reality and his imagination seem to be folding into one another; in particular, he senses a mysterious connection between the life and death of his friend James Pike—a prominent Episcopal bishop who chronicled his own mystical experiences in a book called The Other Side—and his novel Ubik (which Time magazine included on a list of the 100 best novels since 1923—and which may be the next Dick novel to hit the big screen).

The best psychiatrist I ever saw, Dr. Harry Bryan attached to the Hoover Pavilion Hospital, once told me that I could not be diagnosed, due to the unusual life I had led. Since I saw him I have led an even more unusual life and therefore I suppose diagnosis is even more difficult now. Something strange, however, exists in my life and seems to have for a long time; whether it comes from my odd lifestyle or causes the lifestyle I don’t know. But there it is.

For years I’ve felt I didn’t know what I was doing; I had to watch my activities and deduce, like an outsider, what I was up to. My novels, for example. They are said by readers to depict the same world again and again, a recognizable world. Where is that world? In my head? Is it what I see in my own life and inadvertently transfer into my novels and to the reader? At least I’m consistent, since it is all one novel. I have my own special world. I guess they are in my head, in which case they are a good clue to my identity and to what is happening inside me: they are brain prints. This brings me to my frightening premise. I seem to be living in my own novels more and more. I can’t figure out why. Am I losing touch with reality? Or is reality actually sliding toward a Phil Dickian type of atmosphere? And if the latter, then for god’s sake why? Am I responsible? How could I be responsible? Isn’t that solipsism?

It’s too much for me. Like an astrophysicist who by studying a Black Hole causes it to change, I seem to alter my environment by thinking about it. Maybe by writing about it and getting other people to read my writing I change reality by their reading it and expecting it to be like my books. Someone suggested that.

I feel I have been a lot of different people. Many people have sat at this typewriter, using my fingers. Writing my books.

My books are forgeries. Nobody wrote them. The goddam typewriter wrote them; it’s a magic typewriter. Or like John Denver gets his songs: I get them from the air. Like his songs, they—my books—are already there. Whatever that means.

The most ominous element from my books which I am encountering in my actual life is this. In one of my novels, Ubik, certain anomalies occur which prove to the characters that their environment is not real. Those same anomalies are now happening to me. By my own logic in the novel I must conclude that my or perhaps even our collective environment is only a pseudo-environment. In my novel what broke through was the presence of a man who had died. He speaks to them through several intermediary systems and hence must still be alive; it is they, evidently, who are dead. What has been happening to me for over three months is that a man I knew who died has been breaking through in ways so similar to that of Runciter in Ubik that I am beginning to conclude that I and everyone else is either dead and he is alive, or—well, as in the novel, I can’t figure it out. It makes no sense.

Even scarier is that this man, before his death, believed that those who are dead can “come across” to those who are alive. He was sure his own son who had recently died was doing this with him. Now this man is dead and it would seem he is “coming across” to me. I guess there is a certain logic in this. Even more logical is that I and my then wife Nancy participated as a sort of disinterested team observing whether Jim Jr. was actually coming through. It was our conclusion that he was.

On the other hand, I wrote Ubik before Jim Pike died out there on the desert, but Jim Jr. had already died, so I guess my novel could be said to be based on Jim Jr. coming through to his father. So my novel Ubik was based on life and now life is based on it but only because it, the novel, goes back to life. I really did not make it up. I just observed it and put it into a fictional framework. After I wrote it I forgot where I got the idea. Now it has come back to, ahem, haunt me, if you’ll pardon me for putting it that way.

The implication in Ubik that they were all dead is because their world devolved in strange ways, projections onto their environment of their dwindling psyches. This does not carry across to my own life, nor did it to Jim’s when his son “came across.” There is no reason for me to project the inference then of the novel to my own world. Jim Pike is alive and well on the Other Side, but that doesn’t mean we are all dead or that our world is unreal. However, he does seem to be alive and as mentally enthusiastic and busy as ever. I should know; it’s all going on inside me, and comes streaming out of me each morning as I—he—or maybe us both—as I get up and begin my day. I read all the books that he would be reading if he were here and not me. This is only one example. It’ll have to do for now.

Excerpted from The Exegesis of Philip K. Dick, edited by Pamela Jackson and Jonathan Lethem. Copyright © 2011 by Laura Coelho, Christopher Dick, and Isa Hackett. Used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.