出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/07/09 03:34:55」(JST)
| Wikipediaについての議論を行う「メタウィキ」についてはWikipedia:メタウィキメディアをご覧ください。 |
この項目では、接頭語について説明しています。
|
メタ（meta-）とは、「高次な－」「超－」「－間の」「－を含んだ」「－の後ろの」等の意味の接頭語。ギリシア語から。
例えば物質界の現象を超越した世界を取り扱う学問を「形而上学」というが、これは英語でmetaphysicsであり、physics（物理学）の後の学問として存在する（詳しくは「形而上学」の項を参照のこと）。
ある対象を記述したものがあり、さらにそれを対象として記述するものを、メタな○○、あるいは単にメタ○○と呼ぶ。
例えば、WWW上の文章は主にHTMLによって記述されているが、この場合、元の文章に対してHTMLがメタな言語であるといえる。また、HTMLそのものは英語によって仕様が規定されている。この場合、HTMLにとって英語がメタな言語であるといえる。
広義に、何かを取り込んだ何か、何かについての何か、といったものがメタと呼ばれる場合がある。たとえば、Wikipediaの記事一覧の一覧などはメタ的な記事の一つだろう。情報理論では、情報に付加されるそれ自身に関する情報がメタデータ（メタ情報）と呼ばれる。
また、小説をテーマにした小説や、映画をテーマにした映画などがメタな小説（あるいはメタ小説）、メタな映画などという風に言われることがある。この「小説内小説」「映画内映画」と言った入れ子構造は「小説とは何か、映画とは何か」という、それ自体についての自意識を如実に表している（フィクションがフィクションであることを表している）ことが多く、それぞれ研究の対象となる（メタフィクションを参照）。
ベンゼン環の2置換体の構造異性体のうち、2つの置換基が炭素原子1つをはさんでいるものにメタ（meta-、イタリックで、ハイフンをつける）をつける。言い換えれば、1位と3位の炭素原子に置換基があるものである（隣り合う番号は他にもあるが、命名規則により1位と3位となる）。m- と略して書く。
メタに対し、隣（1位と2位）をオルト (ortho- , o-) 、反対側（1位と4位）をパラ (para- , p-) という。
また、ある置換基に注目したとき、その二つ隣の位置をメタ位と呼ぶ。
同じ酸化物を水和して得られるオキソ酸の中で水和度の低いものに、メタ（meta、ハイフンはつけず一語にする）をつける。
メタリン酸、メタホウ酸など。
| この項目は、言語学に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています（ウィキポータル 言語学）。 |
| この項目は、哲学に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています（Portal:哲学）。 |
Meta (from the Greek preposition and prefix meta- (μετά-) meaning "after", or "beyond") is a prefix used in English to indicate a concept which is an abstraction from another concept, used to complete or add to the latter.
In Greek, the prefix meta- is generally less esoteric than in English; Greek meta- is equivalent to the Latin words post- or ad-. The use of the prefix in this sense occurs occasionally in scientific English terms derived from Greek. For example: the term Metatheria (the name for the clade of marsupial mammals) uses the prefix meta- merely in the sense that the Metatheria occur on the tree of life adjacent to the Theria (the placental mammals).
In epistemology, the prefix meta- is used to mean about (its own category). For example, metadata are data about data (who has produced them, when, what format the data are in and so on). In database metadata are also data about data stored in a data dictionary and describes information (data) about database tables such as the table name, table owner, details about columns, – essentially describes the table. Also, metamemory in psychology means an individual's knowledge about whether or not they would remember something if they concentrated on recalling it. The modern sense of "an X about X" has given rise to concepts like "meta-cognition" (i.e. cognition about cognition), "meta-emotion" (i.e. emotion about emotion), "meta-discussion" (i.e. discussion about discussion), "meta-joke" (i.e. joke about jokes), and "metaprogramming" (i.e. writing programs that manipulate programs).[citation needed]
In a rule-based system, a metarule is a rule that governs the application of other rules.[1]
Any subject can be said to have a meta-theory, a theoretical consideration of its properties, such as its foundations, methods, form and utility, on a higher level of abstraction. In linguistics, a grammar is considered as being expressed in a metalanguage, language that operates on a higher level in order to describe properties of the plain language (and not itself).
Meta is also gaining currency as an adjective, as well as a prefix, as in the work of Douglas Hofstadter[citation needed].
The prefix comes from the Greek preposition and prefix meta- (μετά-), from μετά,[2] which meant "after", "beside", "with", "among" (with respect to the preposition, some of these meanings were distinguished by case marking). Other meanings include "beyond", "adjacent" and "self", and it is also commonly used in the form μετα- as a prefix in Greek, with variants μετ- before vowels and μεθ- "meth-" before aspirated vowels.
The earliest attested form of the word "meta" is the Mycenaean Greek me-ta, written in Linear B syllabic script.[3] The Greek preposition is cognate with the Old English preposition mid "with", still found as a prefix in midwife. Its use in English is the result of back-formation from the word "metaphysics". In origin Metaphysics was just the title of one of the principal works of Aristotle; it was so named (by Andronicus of Rhodes) simply because in the customary ordering of the works of Aristotle it was the book following Physics; it thus meant nothing more than "[the book that comes] after [the book entitled] Physics". However, even Latin writers misinterpreted this as entailing that metaphysics constituted "the science of what is beyond the physical".[4] Nonetheless, Aristotle's Metaphysics enunciates considerations of natures above physical realities, which can be examined through this particular part of philosophy, e.g., the existence of God. The use of the prefix was later extended to other contexts based on the understanding of metaphysics to mean "the science of what is beyond the physical".
The OED cites uses of the meta- prefix as "beyond, about" (such as meta-economics and meta-philosophy) going back to 1917. However, these formations are directly parallel to the original "metaphysics" and "metaphysical", that is, as a prefix to general nouns (fields of study) or adjectives. Going by the OED citations, it began to be used with specific nouns in connection with mathematical logic sometime before 1929. (In 1920 David Hilbert proposed a research project in what was called "metamathematics.")
A notable early citation is Quine's 1937 use of the word "metatheorem",[5] where meta- clearly has the modern meaning of "an X about X". (Note that earlier uses of "meta-economics" and even "metaphysics" do not have this doubled conceptual structure – they are about or beyond X but they do not themselves constitute an X).
Douglas Hofstadter, in his 1979 book Gödel, Escher, Bach (and in the sequel, Metamagical Themas), popularized this meaning of the term. The book, which deals extensively with self-reference and strange loops, and touches on Quine and his work, was influential in many computer-related subcultures and is probably largely responsible for the popularity of the prefix, for its use as a solo term, and for the many recent coinages which use it.[citation needed] Hofstadter uses meta as a stand-alone word, both as an adjective and as a directional preposition ("going meta", a term he coins for the old rhetorical trick of taking a debate or analysis to another level of abstraction, as when somebody says "This debate isn't going anywhere"). This book is also probably responsible for the direct association of "meta" with strange loops, as opposed to just abstraction.[citation needed] The sentence "This sentence contains thirty-six letters," and the sentence it is embedded in, are examples of "metasentences" that reference themselves in this way.
| Look up meta- in Wiktionary, the free dictionary. |
全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.
| リンク元 | 「後腎」「variant」「異型」「後脳」「atypical」 |
| 拡張検索 | 「xylometazoline hydrochloride」 |
| 関連記事 | 「met」 |