Phillip K. Dick

I do not advocate the use of psychedelics, however, some insights may be gained from the experience. Those insights are few in number and, since others had them, let them share them with you. Saves you all the chaos that comes from the drugs. The experience is easily conveyed through music and through visual arts, but hard to write about.

Phillip K. Dick, henceforth known as PKD, was a science fiction writer who took LSD a couple of times in the old VA Clinic trials, as did Ken Kesey and the Grateful Dead's lyricist, Robert Hunter. Already a user of amphetamines, the experience had a deep effect on PKD's perception of the world and he was one of the few to turn that into fine writing.

His stories, and he was prolific, often deal with the mutability of reality and personality. Characters seem to slide from one reality into another in an unpredictable manner and people seem to warp from one personality into another. Time also becomes slippery. The effects are mind altering in the reader; you begin to notice how flimsy your own sense of reality, and especially your persona are. Science fiction was the perfect vehicle for his thoughts and he is one of the genre's masters.

I would especially recommend Do Androids Dream of Electric Sheep, The Man in the High Castle, The Transmigration of Timothy Archer, We Can Remember It for You Wholesale, Ubik and The Three Stigmata of Palmer Eldritch. All of these are wonderful, thought provoking and trippy.

In his later life, he died in his 50s, PKD experience a series of visions, not drug induced, and developed a sort of Gnostic Christian viewpoint, although he thought of the spiritual entities he encountered more as living computers than the classic idea of gods and demons. He write a semi-autobiographical novel about this, VALIS. He also did a more formal presentation of his beliefs in The Exegesis  of Phillip K. Dick.

I do not want to leave you with the wrong idea. His works are not sober explorations of complex ideas. The ideas are there but the stories themselves are fascinating and, often, hilariously funny.
So, give your mind a stretch and read a few of his weird stories.