The Non Fiction Writings of Philip K. DIck
Philip K. Dick's body of work includes a number of non fiction texts such as letters, philosophical texts, and the Exegesis, where he tries to explain, over thousands of pages, what happened to him during his "2-3-74" experience. Of note is the six volume collection of his letters, THE SELECTED LETTERS OF PHILIP K. DICK, which are rich in biographical information.
Letters
 The Dark Haired Girl Ziesing, 1988 |  The Selected Letters of Philip K. Dick 1938-1971 Underwood Books, 1996 |  The Selected Letters of Philip K. Dick 1972-1973 Underwood Books, 1993 |  The Selected Letters of Philip K. Dick 1973-1974 Underwood Books, 1991 |  The Selected Letters of Philip K. Dick 1975-1976 Underwood Books, 1992 |
 The Selected Letters of Philip K. Dick 1977-1979 Underwood Books, 1992 |  The Selected Letters of Philip K. Dick 1980-1982 Underwood Books, 2008 |
Philosophical Texts
 Cosmogony and Cosmology Kerosina, 1987 |  Cosmogony and Cosmology Kerosina, 1987 |  Cosmogony and Cosmology Kerosina, 1987 |  Pursuit of Valis Underwood Miller, 1991 |  Pursuit of Valis Underwood Miller, 1991 |
 The Shifting Realilties of Philip K. Dick Random House, 1995 |  The Shifting Realilties of Philip K. Dick Vintage, 1996 |  The Exegesis of Philip K. Dick Houghton Mifflin Harcourt, 2011 |
Anthologized Texts
 Science Fiction at Large Harper and Row, 1976 |  Science Fiction at Large Gollancz, 1977 |