'"Tlön, Uqbar, Orbis Tertius" is a 1940 Magic Realism short story by Jorge Luis Borges. Although it's only a few thousand words long and not a particularly easy read, it quickly became one of the most influential works of fiction of the 1940's.
The report begins with an unnamed narrator, who becomes fascinated with the land of "Uqbar" that a friend tells him of. Uqbar, as it turns out, only exists in an article found in only one copy of one edition of The Anglo-American Cyclopaedia, and the article is mostly self-referential.
Slowly, however, more details on Uqbar start finding their way into the narrator's life. The purported nation seemingly once had an extensive mythology, based around the mythical land of Tlön. Tlön's philosophy and linguistics paint a fascinating picture of a holistic mysticism. Using the mindset of this mythical land, its inhabitants could allegedly find things simply by expecting to find them, regardless of whether or not these things existed previously. In the minds of these mythical Tlön people that the Uqbar culture spoke of, simply thinking, or writing, about objects and events could cause them to be real.
The narrator decides that both Uqbar and its stories of Tlön can only be inventions of a particularly creative author — or rather, a group of natural scientists and philosophers who combined their knowledge to create such complicated Worldbuilding.
Provides examples of:
- Author Appeal: Reference materials as an intersection between fiction and reality. Labyrinths. Footnotes. Literary criticism.
- Death of the Author: Discussed In-Universe. In accordance with their disbelief in discrete objects (see Starfish Language), Tlönese literary criticism is said to involve attributing unrelated stories to the same author and analysing the implications for the author's worldview.
- Direct Line to the Author: The narrator is implicitly Borges himself, sharing his interests and backstory, and telling the story in the first-person as though reporting on events he has personally connected and interviewed witnesses for.
- Hollywood Atheist: The 19th-century millionaire who agreed to fund the creative endeavors of Orbis Tertius, strictly on the grounds that the completed work "have nothing to do with the impostor, Jesus Christ".
- Language Equals Thought: Their strange language leads to the people of Tlön developing a philosophy similar to Berkeleyan idealism, but without his benevolent God.
- Mind Screw: Falsified encyclopaedia entries lead to changes in consensus reality, up to the point of physically implausible objects (like Tlön's unnaturally dense conical coins) being retconned into existence.
- Postmodernism: The last few paragraphs give away that the story is basically a rant against dogmatic, self-complete "grand narratives" like Nazism or communism that purport to explain everything in the world but only end up explaining themselves. The story was written during the onset of World War II, which means it actually predates postmodernism proper.
- Rewriting Reality: In a fashion which is something of a mathematical joke. Uqbar exists only in the tampered pages of the Anglo-American Cyclopedia; Tlön exists only in the mythology of Uqbar. Tlön is therefore unreal on two levels, which is a double negative, so it starts to become real.
- Starfish Language: The languages of Tlön have no nouns but only verbs and adjectives, reflecting the philosophy of its speakers (they see the world not as a set of objects with continuity in time, but a succession of events and transitory qualities). The phrase "The moon rose above the river" is translated into Tlönian as Hlör u fang axaxaxas mlö, which approximates to "Upward behind the onstreaming it mooned."
- Unreliable Narrator: Conversed. The story begins with the narrator and his friend discussing how one might write a novel with a narrator so subtly unreliable that only a few perceptive readers would discover the truth.
- Your Mind Makes It Real: The people of Tlön believe it, and uncritical Cyclopedia readers believe that Uqbar believes Tlön believes it, which allows Tlön to creep into reality. In other words, Your Mind Makes "Your Mind Makes It Real" Real.