I once read a collection of short stories from across Dick's entire career. His early stories were pleasingly quirky, but as the Sixties and Seventies wore on, the tone of his writing just became more and more out-there.
It's easy to say that Dick slowly went insane. Indeed, looking at his biography, that does appear to be the case. But if he went insane, he was well aware of the fact as it was happening.
What sort of novel would a highly intelligent, well-read person whose mind is turning inside out write? Well, he would write VALIS.
I actually started VALIS last year, but put it down again because I was in the mood for something more akin to a traditional novel. VALIS reads more like a couple of characters discussing difficult, abstruse philosophy, in the context of 1970s California.
There was one bit that I gleaned from my first attempt, that I absolutely loved. I learned about the two-proposition self-cancelling structure. In layman's terms, this is an argument of the form 'A. Also, B.' where B looks like it reinforces A, but in fact it negates it.
1. God does not exist.
2. And what's more, he's stupid.
Everybody go have fun looking for real-life examples of this structure.
The plot, to the extent that there is one, concerns main character Horselover Fat's attempts to build a valid philosophy based on Gnosticism after a friend of his commits suicide. Gnosticism is an ancient philosophy I have a hard time getting my head around, even though I know it's got elements in common with Hinduism and Buddhism and also resembles many quite modern ways of looking at the universe. I still can't say I retained very much of Horselover Fat's philosophy.
VALIS is narrated in the first person by Phil. Phil is Philip K. Dick. Within the narrative Phil even mentions real-life books he's written in the past. Horselover Fat, the main protagonist, is also Philip K. Dick. This is made very clear at several points in the narrative. Phil and Horselover Fat share many conversations about philosophy. There's one point where Horselover Fat travels the world and sends letters back to Phil back in California. Go ponder that and report back to me when you're finished.