The book was dedicated in part to science fiction author Philip José Farmer, who had explored sexual themes in works such as The Lovers (1952).- Existence (Wikipedia)
Existence is the ability of an entity to interact with reality. In philosophy, it refers to the ontological property of being.
- Stranger in a Strange Land (Wikipedia)
Stranger in a Strange Land is a 1961 science fiction novel by American author Robert A. Heinlein. It tells the story of Valentine Michael Smith, a human who comes to Earth in early adulthood after being born on the planet Mars and raised by Martians, and explores his interaction with an eventual transformation of Terran culture.