He also was a total loony, certified paranoid schizophrenic, and like many other great artists used a huge amount of drugs; mainly speed but everything else too. Phil used drugs to travel to the limits of human psyche sacrificing his own sanity in the process. But he sent us a beautiful and useful message back from there and it is right there in his books. If some smart kid there wanna try hard drugs like weed or heroine out of pure curiosity, don't do it. I can tell you from experience that they are addictive and in the end they just make you miserable. Make you sad. Instead read Ubik to find out exactly how they gonna mess your brain up. Main point is that you don't have to alter your mind with any substances to understand Dick's books. My sister likes him and she's as straight as they come, a doctor like his husband, mother of two little girls, drinks fucking decaf. Personally I've read him high, slow and low but the books have given me most when I've read them sober. Like I'm on Phil's trip so I don't have to take anything that makes me sick afterwards.
Mr. Dick is best known for the hit films like Minority Report adapted from his books. But he should be best known for his novels. He didn't write any scripts or screenplays in his entire life (1928-1982), only novels and short stories. I've seen most of the movies based on his writings and think they're OK but only Blade Runner is as good as them books. Movie critics say pretty much the same.
His novels, on the other hand, are pure fucking mindblowing magic. Sci-fi stories are usually based on one single idea like time travel attempting to give the reader a "sense of wonder". One idea is enough for a totally perfect short story of about 10-50 pages, but not for even a satisfactory novel of 300 pages. That's why most of the best sci-fi literature are short stories. Dick's short stories are great too.
Writers of the very best short stories make novels using one single meaningful twist of reality, for example some sort of telepathy, adding some unimportant differences like beings with three hands not once using the third and ray guns which are used exactly like assault rifles; the hero starting from scratch fights enemies and overcomes obstacles with his furry, metallic or in some other way "different" friends preventing disaster and restoring peace and finally getting the Xrythian princess or whatever.
Philip K. Dick's novels are not like that. I can't really say about all 43 of them, but I've never heard or read anyone badmouthing anything else than his three last books which are about his Gnostic religion. Well hey, the man was dying and he knew it. The 18 that I have read include those controversial final three and I think the last is only good but the other two great; some of that Gnostism really makes sense. His books generally have several distortions from reality and everything matters, the Zap Gun is not used like an assault rifle and if he had written about earth with three-handed people otherwise like us their whole culture would differ from our world, don't ask me how exactly, I'm no Phil K.
Anyway his books ain't about guns or swords but his characters who live and learn like they must as they get sent back and forth in time while their brain splits until they find out they only exist in a machine or something completely different. And it's not about their psychobabble father-son relations, it's partly a veiled message about the then raging cold war and other political stuff where Phil was about right: Soviets were just sugar-coated Nazis but McCarthy, Vietnam, Nukes and Nixon weren't good for mental health either. But most of all it's about the very deepest stuff: philosophy, religion and just staying sane. It has been rightfully said that no author has influenced contemporary philosophy more than Philip K. Dick. That is still true 25 years after his death. He also pretty much defined science fiction in the 60's and 70's and is the godfather of cyberpunk. Without him there wouldn't be no Terminator or Matrix.
Time Out of Joint, The Man in the High Castle, The Simulacra, Clans of the Alphane Moon, The Three Stigmata of Palmer Eldrich, Now Wait for Last Year, Ubik, Flow my Tears the Policeman Said, A Scanner Darkly, Lies Inc. and for freaks interested in Gnostism VALIS and The Divine Invasion.