Philip K. Dick developed what would later be called cyberpunk. Many of his works are about themes from sociology. Often, politics also play an important role. Very often there are Authoritarian Governments, and very powerful companies in his books. In his later books, Dick writes about drug use. He writes about characters that have paranoia or schizophrenia. In novels such as "A Scanner Darkly" or "VALIS" he uses his own experiences.