The Treachery Of Images (1928-29) by René Magritte depicts a pipe along with text stating "This is not a pipe."

Self-reference occurs in natural or formal languages when a sentence, idea or formula refers to itself. The reference may be expressed either directly—through some intermediate sentence or formula—or by means of some encoding. In philosophy, it also refers to the ability of a subject to speak of or refer to himself, herself, or itself: to have the kind of thought expressed by the first person pronoun, the word "I" in English.

Self-reference is studied and has applications in mathematics, philosophy, computer programming, and linguistics. Self-referential statements are sometimes paradoxical.

  Usage

  The Ouroboros, a dragon that continually consumes itself, is used as a symbol for self-reference.^{[citation needed]}

An example of a self-referential situation is the one of self-creation, as the logical organization produces itself the physical structure which creates itself.^{[citation needed]}

In metaphysics, self-reference is subjectivity, while "hetero-reference", as it is called (see Niklas Luhmann), is objectivity.^{[citation needed]}

Self-reference also occurs in literature and film when an author refers to his work in the context of the work itself. Famous examples include Cervantes's Don Quixote, Denis Diderot's Jacques le fataliste et son maître, Italo Calvino's If on a winter's night a traveler, many stories by Nikolai Gogol, Lost in the Funhouse by John Barth, Luigi Pirandello's Six Characters in Search of an Author, and Federico Fellini's 8½ . This is closely related to the concepts of breaking the fourth wall and meta-reference, which often involve self-reference.

The surrealist painter René Magritte is famous for his self-referential works. His painting The Treachery of Images, shown above, includes the words this is not a pipe, the truth of which depends entirely on whether the word "ceci" (in English, "this") refers to the pipe depicted—or to the painting or the sentence itself.

In computer science, self-reference occurs in reflection, where a program can read or modify its own instructions like any other data. Numerous programming languages support reflection to some extent with varying degrees of expressiveness. Additionally, self-reference is seen in recursion (related to the mathematical recurrence relation), where a code structure refers back to itself during computation.

  Examples

  In language

A word that describes itself is called an autological word (or autonym). This generally applies to adjectives, for example sesquipedalian, but can also apply to other parts of speech, such as TLA, as a three-letter abbreviation for three-letter abbreviation, and PHP which is a recursive acronym for "PHP: Hypertext Preprocessor".

A reflexive sentence has the same subject and object (e.g., "The man washed himself"). In contrast, a transitive sentence requires the subject and object to be non-identical (e.g., "The man hit John").

There is a special case of meta-sentence in which the content of the sentence in the metalanguage and the content of the sentence in the object language are the same. Such a sentence is referring to itself. However some meta-sentences of this type can lead to paradoxes. "This is a sentence." can be considered to be a self-referential meta-sentence which is obviously true. However "This sentence is false" is a meta-sentence which leads to a self-referential paradox.

Self-referential sentences include "This sentence contains thirty-eight letters.", and Quine's paradox of "Yields falsehood when preceded by its quotation" which yields falsehood when preceded by its quotation.

Fumblerules are a humorous list of rules of good grammar and writing, demonstrated through sentences that violate those very rules, such as "Avoid cliches like the plague" and "Don't use no double negatives". The term was coined in a published list of such rules by William Safire.

  In mathematics

• Impredicativity
• Loop (graph theory)
• Tupper's self-referential formula

Hofstadter's law, which specifies that "It always takes longer than you expect, even when you take into account Hofstadter's Law"^[1] is an example of a self-referencing adage.

  In cognition

Neuroscience research suggests the existence of neuroplasticity, a phenomenon in which thinking processes unconsciously change the neural circuitry and structure of the brain via sensory experience, input from the environment or reactions hitherto.^[2]

  In popular culture

Literature

• The sub-genre of "recursive science fiction" is now so extensive that it has fostered a fan-maintained bibliography at the New England Science Fiction Association's website; some of it is about science fiction fandom, some about science fiction and its authors.^[3]
• Paul Auster's The New York Trilogy, specifically City Of Glass.
• Miguel de Cervantes mentions his own work La Galatea and the novel Don Quixote itself in the novel Don Quixote. A character of an apocryphal version of Don Quixote acknowledges that Cervantes' Don Quixote and Sancho Panza are the real ones and not those of the apocryphal text, which implies that the reader is one of the characters of the novel.
• Dave Eggers's A Heartbreaking Work of Staggering Genius has characters referring to their role in the book and references to the book itself.
• Michael Ende's The Neverending Story uses self-reference of the book prominently, when a character (Bastian) of a story within the story (also called 'Neverending Story') finds a book called the same, and it is the same book the reader is reading.
• Jostein Gaarder's Sophie's World, in which the titular character realizes she is the character in a book.
• Robert A. Heinlein's The Cat Who Walks Through Walls considers the universe, or multiverse, as an author-manipulated object, including the plot of the book itself.
• The title of Abbie Hoffman's Steal This Book is self-referential
• Douglas Hofstadter's Gödel, Escher, Bach uses self-referencing mathematical (formal language) and English (natural language) sentences, pictures (M.C. Escher's dragon for example), and music (Bach's fugues) to convey the concept and its recursive nature.
• James Joyce's Finnegans Wake contains multiple references to itself.
• Spike Milligan's comic novel Puckoon features several arguments between the protagonist Dan Mulligan and the author, after Dan is made aware that he is a fictional character.
• Luigi Pirandello's Six Characters in Search of an Author involves a collection of people that show up at a play rehearsal, claiming to be characters in search of a playwright to help them finish their story. The play plays itself out as a way of (possibly) doing just that.
• The Sesame Street book The Monster at the End of This Book references itself in the title, as well as throughout the story.
• In Clifford D. Simak's 1951 novel Time and Again, the main character travels back in time to 1977 and meets a man who calls himself "Old Cliff", who mentions that he had written a book about the very same theme as the novel itself.
• In Miguel de Unamuno's novel Niebla ("Fog") the main character, Augusto Pérez, confronts Unamuno himself and has a quarrel with his author and inventor, reproaching Unamuno to have created him.
• Kurt Vonnegut refers to himself as the author in his novel Breakfast of Champions, where he has a conversation with himself about the writing of the novel itself. The character Kilgore Trout also engages in a conversation with the author.
• Robert Anton Wilson's Schrödinger's Cat Trilogy takes place in a universe where the books of the trilogy exist. Indeed, a character named Robert Wilson exists in the third book, and he is aware that he is a character in a book, having read the book and found himself described there.

Film

• In Mel Brooks' 1974 film Blazing Saddles the villain is killed outside a movie theater premiering Blazing Saddles. Similarly, Brooks' 1987 film Spaceballs uses the video release of the movie that the audience is watching to see what will happen in the future.
• Some Monty Python sketches involves characters consulting or referring to the script to determine what to do next. Their film Monty Python and the Holy Grail is extensively self-referencing, including numerous on-screen references to incidents in "Scene 24"; soundtrack music being repeatedly noticed and silenced by a character; a sotto voce admission that a castle is "only a model", and the like.
• The 2006 film Stranger Than Fiction is about a character's knowledge that he is apparently living out a story written by an author, complete with narration which is audible to him. He eventually confronts the author, identifying himself as a character from one of her books.
• Several classic Warner Bros. Looney Tunes animated cartoons show characters going into a movie theatre, where they watch a version of the cartoon they're in.

Comics

• In DC Comics' Legion of the 3 Worlds, The main antagonist, Superboy Prime, is the Clark Kent from a destroyed iteration of the real universe, supremely displeased from how his favourite comic books turned out while journeying in their multiverse (depicted as coexisting with the real one). Eventually, Clark returns to our dimension, where is confronted by his distraught parents and girlfriend, having read the chronicles of his villainous action from the comic books published after his "departure".
• In the Tintin adventure "Cigars of the Pharaoh", Tintin finds himself the relenting guest of a sheikh who recognizes him and shows him another album of his adventures. In earlier editions, the album was Tintin in America, then Tintin in the Congo in the color version. But later (current) editions go even further by showing the album cover of an adventure yet to come (Destination Moon) at the time of the story, but which is by now known by modern readers of earlier adventures.

Plays

• In Ain and David Gordon's Obie Award-winning play The Family Business, a character who is a playwright is asked what he is writing. "This," he replies, "I'm writing this."

Music

• The folk song "Goober Peas", which dates from around the time of the American Civil War contains the lyrics: I think my song has lasted almost long enough. / The subject is most interesting, but rhymes are mighty tough.
• In Arlo Guthrie's 1967 recording of his song/monologue "Alice's Restaurant", he says at one point to the live audience he's performing for: "I've been singing this song for 45 minutes now, I can sing it for another 45; I'm not tired ... or proud."
• Carly Simon's song "You're So Vain", which contains the lyrics, "You're so vain, you probably think this song is about you."
• Da Vinci's Notebook's song "Title of the Song" is composed entirely of self-references.

  See also

  References

Notes

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (July 2011)

Bibliography

• Hofstadter, D. R. (1980). Gödel, Escher, Bach: an Eternal Golden Braid. New York, Vintage Books.
• Smullyan, Raymond (1994), Diagonalization and Self-Reference, Oxford Science Publications, ISBN 0-19-853450-7

  External links

• Self-Referential Story, from the Internet Oracularities #1353
• Self-Referential Aptitude Test, by Jim Propp
• Self-reference and apparent self-reference
• Self-reference jokes
• The Paradox of Self-Amendment: A Study of Logic, Law, Omnipotence, and Change, by Peter Suber (Peter Lang Publishing, 1990). A book-length study of self-reference in law. (Out of print, but the full text is available online)
• University of Wisconsin-Milwaukee (at archive.org) Self-Reference in ``Self-Reference in `Self-Reference in ...'", a review of a review of a review of ... (archived at WebCite)