Next year SF celebrates a fairly significant anniversary. It will be 40 years since JG Ballard published The Terminal Beach , Brian Aldiss published Greybeard , William Burroughs published Naked Lunch in the UK, I took over New Worlds magazine and Philip K Dick published The Three Stigmata of Palmer Eldritch . It was a watershed year, if you like, when SF rediscovered its visionary roots and began creating new conventions which rejected both modernism and American pulp traditions.

Perhaps best representing that cusp, Dick's work only rarely achieved the stylistic and imaginative coherence of those other writers. His corporate future came from a common pool created by troubled left-wingers Pohl and Kornbluth ( The Space Merchants , 1953) or Alfred Bester ( The Demolished Man , 1953). His Mars is the harsh but habitable planet of Leigh Brackett ( Queen of the Martian Catacombs , 1949) or Ray Bradbury ( The Martian Chronicles , 1950). His style and characters are indistinguishable from those of a dozen other snappy pulpsters. Even his questioning of the fundamentals of identity and reality is largely unoriginal, preceded by the work of the less prolific but perhaps more profound Charles Harness, who wrote stories such as "Time Trap", "The Paradox Men" and "The Rose" in the 50s.

So how has Dick emerged as today's best-known and admired US SF writer? It's hard to judge from this book (which was promoted enthusiastically by me and many others when it first appeared).