Philip K. Dick Quotes
The psychotic does not merely think he sees four blue bivalves with floppy wings wandering up the wall; he does see them. An hallucination is not, strictly speaking, manufactured in the brain; it is received by the brain, like any 'real' sense datum, and the patient act in response to this to-him-very-real perception of reality in as logical a way as we do to our sense data. In any way to suppose he only 'thinks he sees it' is to misunderstand totally the experience of psychosis.
Dick, Philip K. "Schizophrenia & The Book of Changes." The Shifting Realities of Philip K. Dick: Selected Literary and Philosophical Writings, edited by Lawrence Sutin, Pantheon Books, 1995.
Philip Kindred Dick was an American writer known for his work in science fiction. He wrote 44 published novels and approximately 121 short stories, most of which appeared in science fiction magazines during his lifetime. His fiction explored varied philosophical and social themes, and featured recurrent elements such as alternate realities, simulacra, monopolistic corporations, drug abuse, authoritarian governments, and altered states of consciousness. His work was concerned with questions surrounding the nature of reality, perception, human nature, and identity.