janusとは 意味・読み方・使い方

語源

A statue of the Roman god Janus (sense 1) in the collection of the Museum of Ferrara Cathedral in Ferrara, Italy. Janus is traditionally depicted as having two faces, one looking to the past and the other the future.

Janus (sense 5), one of the planet Saturn’s moons, photographed by the Cassini–Huygens space probe on 7 April 2010

From Latin Iānus (“the Roman god Janus”).

発音

• (Received 発音, General American) enPR: ˈjā.nəs IPA^(key): /ˈd͡ʒeɪnəs/
• (General Australian) IPA^(key): /ˈdʒæɪ̯nəs/
• ハイフネーション: Ja‧nus
• 韻: -eɪnəs

固有名詞

Janus

1. (Roman mythology) The god of doorways, gates and transitions, and of beginnings and endings, having two faces looking in opposite directions.
   • 1789, Edward Gibbon, chapter XLI, in The History of the Decline and Fall of the Roman Empire, volume V, London: Printed for A[ndrew] Strahan, and T[homas] Cadell, in the Strand, OCLC 30106274; republished Philadelphia, Pa.: Published by William Y. Birch & Abraham Small, No. 37, South Second Street; printed by Robert Carr, 1805, OCLC 15453273, page 166:

     In the ages of victory, as often as the senate decreed some distant conquest, the consul denounced hostilities, by unbarring, in solemn pomp, the gates of the temple of Janus. Domestic war now rendered the admonition superfluous, and the ceremony was superseded by the establishment of a new religion. But the brazen temple of Janus was left standing in the forum; of a size sufficient only to contain the statue of the god, five cubits in height, of a human form, but with two faces, directed to the east and west.

   • 1797, Titus Livius [Livy]; George Baker, transl., The History of Rome, [...] In Six Volumes, volume I, London: Printed for A[ndrew] Strahan, and T[homas] Cadell Jun. and W. Davies (successor to Mr. Cadell) in the Strand, OCLC 314578224, book I, page 35:

     [K]nowing that the minds of the people, rendered ferocious by a military life, would never accommodate themſelves to the practice of theſe [principles of justice, laws, and morals], during the continuance of war, he [Numa Pompilius] reſolved, by a diſuſe of arms, to mollify the fierceneſs of their temper: with this view, he built a temple to Janus, near the foot of the hill Argiletum, which was to notify a ſtate either of war or of peace: when open, it denoted that the ſtate was engaged in war; when ſhut, that there was peace with all the ſurrounding nations.

   • 1810, anonymous [Susan Edmonstone Ferrier], “chapter XVI”, in Marriage, a Novel. In Three Volumes, volume II, Edinburgh: William Blackwood, Prince's-Street: and John Murray, Albemarle-Street, London, published 1818, OCLC 81878524, page 218:

     "I'll tell you what we can do," cried her persevering patroness; "we can go as masks, and Lady Juliana shall know nothing about it. That will save the scandal of an open revolt or a tiresome dispute. Half the company will be masked; so, if you keep your own secret, nobody will find it out. Come, what characters shall we choose?" / "That of Janus, I think, would be the most suitable for me," said Mary.

   • 1879 February 27, A[lexander] M[artin] Sullivan, “On the Zulu War” (speech before the House of Commons of the United Kingdom); quoted in William Jennings Bryan, editor, Irish Orations (The World's Famous Orations), volume VI, New York, N.Y.: Funk & Wagnalls, 1906, OCLC 23127203, and republished on Bartleby.com^[1], 2002, archived from the original on 4 October 2015:

     We find ourselves once again sitting in Committee of the Whole House to vote a war subsidy. The present occupants of the Treasury Bench are determined that so long as they retain their places the Temple of Janus shall not be closed.

   • 2008, John Lowe, “Laughin’ up a World: Their Eyes Were Watching God and the (Wo)Man of Words”, in Harold Bloom, editor, Interpretations: Zora Neale Hurston’s Their Eyes Were Watching God (Bloom’s Modern Critical Interpretations), new edition, New York, N.Y.: Bloom's Literary Criticism, Infobase Publishing, →ISBN, page 75:

     Janus, with his two heads, his mystery, his depiction as both laughing and serious, and the obvious parallel this forms with the masks of attic tragedy and comedy would make him a double of the two-headed man, the conjurer, and an associate of the trickster in folk comedy as well.

   • 2011, Robert M. Hodapp, “Preface”, in Robert M. Hodapp, editor, International Review of Research in Developmental Disabilities, volume 41, San Diego, Calif.: Academic Press, →ISBN, ISSN 2211-6095, page xi:

     Good reviews look both backward and forward; an argument could even be made that one must look backward in order to discern the way forward, that backward and forward are two sides of the same research coin. Nowhere is such a Janus-like perspective more apparent than in the current set of reviews.

2. (attributively) Used to indicate things with two faces (such as animals with diprosopus) or aspects; or made of two different materials; or having a two-way action.

   Janus cat, Janus particle

   • 1996, Scott B. Noegel, “Introduction to Janus Parallelism”, in Janus Parallelism in the Book of Job (Journal for the Study of the Old Testament Supplement Series; 223), Sheffield: Sheffield Academic Press, →ISBN, page 12:

     But other categories of word-play have not been researched extensively or systematically. Among the latter is the type of word-play known as polysemous parallelism, or more commonly, Janus parallelism. The latter term was coined by Cyrus Gordon to describe a literary device in which a middle stich of poetry parallels in a polysemous manner both the line that precedes it and the line which follows it.

   • 2004, Ad Zuiderent, “The Historical Pole of the Earth: Time in the Novels of Gerrit Krol”, in Thomas F[rederic] Shannon and Johan P[ieter] Snapper, editors, Janus at the Millennium: Perspectives on Time in the Culture of the Netherlands (Publications of the American Association for Netherlandic Studies; 15), Lanham, Md.: University Press of America, →ISBN, page 93:

     The novel seems to be rather autobiographical, but in retrospect one can see about three-quarters through the text there is a turn from an autobiographical into a future novel […]. De chauffeur verveelt zich is a real Janus-novel, looking into two directions.

   • 2012, Ruby L. Agnir, “Janus”, in Upward beyond the Brim: Transcending the Limits: Selected Writings, [Bloomington, Ind.]: Xlibris, →ISBN:

     The ability to look at both sides of a coin before giving a verdict can be both a curse and a blessing. […] This "Janus effect" (my term) is a curse when it blocks a time sensitive judgment response, or a decision waiting to be made before long. […] Friendships, sibling harmony, good relationship with associates at work, and especially marriages, could be great and positive recipients of the good that such a Janus effect could bring on.

   • 2013, Riccardo Fantoni, “What is a Janus Fluid?”, in The Janus Fluid: A Theoretical Perspective (Springer Briefs in Physics), Cham, Switzerland: Springer, DOI:10.1007/978-3-319-00407-5_1, →ISBN, ISSN 2191-5423, page 1:

     A Janus fluid is one made of Janus particles immersed in a solvent. A Janus particle like the Roman God Janus, […] is one that has two faces with two different functionalities.

   1. (chemistry, attributively) Used to indicate an azo dye with a quaternary ammonium group, frequently with the diazo component being safranine.

      Janus green B is a dye used widely in histology to stain cells for microscopic examination.

      • 1921, Textile Colorist, volume 43, New York, N.Y.: Howes Publishing Company, ISSN 0096-5901, OCLC 2715803, page 401:

        In order to show that such stains are due to oxycellulose, the fabric should be stripped with titanous chloride solution or sodium hydrosulphite. On redyeing with Janus Blue the oxycellulose patches are more heavily dyed. The writer prefers Janus Blue to the Methylene Blue which is usually recommended.

      • 1943, Edmund Vincent Cowdry, Microscopic Technique in Biology and Medicine, Philadelphia, Pa.; Baltimore, Md.: Lippincott Williams & Wilkins, OCLC 615034302, page 102, column 1:

        Janus Dyes. Named after the God, Janus with two faces since they often exhibit two colors.

      • 1990, László Módis, “Topo-optical Reactions Used in Polarization Microscopic Ultrastructure Research”, in Organization of the Extracellular Matrix: A Polarization Microscopic Approach, Boca Raton, Fla.: CRC Press, →ISBN, page 40:

        The significance of the molecular shape of the dyes in induction of the birefringence of polyanions is illustrated with topo-optical reactions of the Janus dyes. Janus red, yellow, green, black, and blue are cationic azo dyes […]. All of these exhibit a moderate metachromatic effect with sulfated GAGs [glycosaminoglycans].

      • 1993, David E. Sadava, “Mitochondria”, in Cell Biology: Organelle Structure and Function, Boston, Mass.; London: Jones and Bartlett Publishers, →ISBN, page 93:

        In 1900, L[eonor] Michaelis (who later became famous for his studies of enzyme kinetics) found that mitochondria in living cells could be specifically stained by the dye Janus Green B […]. Because this dye must be oxidized to become colored, Michaelis proposed that mitochondria are cellular oxidizing agents.

3. (figuratively) A two-faced person, a hypocrite.
   • 1814, Selina Davenport, The Hypocrite; or, The Modern Janus. A Novel. In Five Volumes, volume I, London: Printed at the Minerva-Press, for A. K. Newman and Co. Leadenhall-Street, OCLC 6737585, title page:

     The hypocrite; or, The modern Janus.

4. A moon of Saturn.
   • 2012 October, “Saturn”, in Martin Rees, editor, Universe, rev. edition, London: Dorling Kindersley, →ISBN, page 192:

     Heavily cratered and irregularly shaped, Janus orbits Saturn just beyond the F ring and only 50km (30 miles) farther away than its co-orbital moon, Epimetheus.

   • 2016, Michael [W.] Carroll, “Ice Dwarfs and Tiny Moons”, in Picture This!: Grasping the Dimensions of Time and Space, Cham, Switzerland: Springer Nature, DOI:10.1007/978-3-319-24907-0, →ISBN, page 56:

     Two of Saturn's small moons have the unique distinction of sharing the same orbit. Epimetheus and Janus circle the Lord of the Rings at a distance of just over 151,000 km, about half the distance from Earth to the Moon. Both are irregularly shaped. Janus is 179 km across, while Epimetheus is about 116 km in diameter.

使用する際の注意点

The doors of the temple of Janus were traditionally open only during the time of war and closed to mark the end of the conflict. Thus, the temple of Janus may be used metaphorically to mean conflict or wartime (see the 1879 quotation above).

派生語

Further reading

• Janus on Wikipedia.
• Janus (moon) on Wikipedia.

アナグラム

• Sanju, Sunja