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Georg Henrik von Wright

Georg Henrik von Wright (14 June 1916 – 16 June 2003) was a Finnish philosopher.

Biography
G. H. von Wright was born in Helsinki on 14 June 1916 to Tor von Wright and his wife Ragni Elisabeth Alfthan.

On the retirement of Ludwig Wittgenstein as professor at the University of Cambridge in 1948, von Wright succeeded him. He published in English, Finnish, German, and Swedish, belonging to the Swedish-speaking minority of Finland. Von Wright was of both Finnish and 17th-century Scottish ancestry, and the family was raised to nobility in 1772.

Work
Von Wright's writings come under two broad categories. The first is analytic philosophy and philosophical logic in the Anglo-American vein. His 1951 texts An Essay in Modal Logic and "Deontic Logic" were landmarks in the postwar rise of formal modal logic and its deontic version. He was an authority on Wittgenstein, editing his later works. He was the leading figure in the Finnish philosophy of his time, specializing in philosophical logic, philosophical analysis, philosophy of action, philosophy of language, epistemology, and the close study of Charles Sanders Peirce.

The other vein in von Wright's writings is moralist and pessimist. During the last twenty years of his life, under the influence of Oswald Spengler, Jürgen Habermas and the Frankfurt School's reflections about modern rationality, he wrote prolifically. His best known article from this period is entitled "The Myth of Progress" (1993), and it questions whether our apparent material and technological progress can really be considered "progress" (see Myth of Progress).

Awards
In the last year of his life, he was awarded several honorary degrees, including one by the University of Bergen. He also was awarded the Swedish Academy Finland Prize in 1968.

Publications

 * The Logical Problem of Induction, PhD thesis, 31 May 1941
 * Den logiska empirismen (Logical Empirism), in Swedish, 1945
 * Über Wahrscheinlichkeit (On Chance), in German, 1945
 * An Essay in Modal Logic, (Studies in Logic and the Foundations of Mathematics: Volume V), L.E.J. Brouwer, E.W. Beth, and A. Heyting (eds.), Amsterdam: North-Holland,1951
 * A Treatise on Induction and Probability, 1951
 * "Deontic Logic" Mind, 60: 1–15, 1951
 * Tanke och förkunnelse (Thought and Preaching), in Swedish, 1955
 * Logical Studies, 1957
 * Logik, filosofi och språk (Logic, philosophy and language), in Swedish, 1957
 * The Varieties of Goodness, 1963. (1958–60 Gifford Lectures in the University of St. Andrews. He considered this his best and most personal work.)
 * Norm and Action, 1963 (1958–60 Gifford Lectures, St. Andrews. )
 * The Logic of Preference, 1963
 * Essay om naturen, människan och den vetenskaplig-tekniska revolutionen (Essay on Nature, Man and the Scientific-Technological Revolution), in Swedish, 1963
 * An Essay in Deontic Logic, 1968
 * Time, Change and Contradiction, (The Twenty-Second Arthur Stanley Eddington Memorial Lecture Delivered at Cambridge University 1 November 1968) Cambridge University Press. 1969
 * Tieteen filosofian kaksi perinnettä (The Two Traditions of the Philosophy of Science), in Finnish, 1970
 * Explanation and Understanding, 1971
 * Causality and Determinism, 1974
 * Handlung, Norm und Intention (Action, Norm and Intention), in German, 1977
 * Humanismen som livshållning (Humanism as an approach to Life), in Swedish, 1978
 * Freedom and Determination, 1980
 * Wittgenstein, 1982
 * Philosophical Papers I–III, 1983–1984
 * v. I Practical Reason, v. II Philosophical Logic, v. III Truth, Knowledge, and Modality
 * Of Human Freedom, 1985. (1984 Tanner Lectures at the University of Helsinki)
 * Filosofisia tutkielmia (Philosophical Dissertations), in Finnish, 1985
 * Vetenskapen och förnuftet (Science and Reason), in Swedish, 1986
 * Minervan Pöllö (The Owl of Minerva), in Finnish, 1991
 * Myten om framsteget (The Myth of Progress), in Swedish, 1993
 * The Tree of Knowledge and Other Essays, Leiden, Brill., 1993
 * Att förstå sin samtid (To Understand one's own Time), in Swedish, 1994
 * Six Essays in Philosophical Logic. Acta Philosophica Fennica, Vol. 60, 1996
 * Viimeisistä ajoista: Ajatusleikki (On the End Times: A Thought Experiment.), in Finnish, 1997
 * Logiikka ja humanismi (Logic and Humanism), in Finnish, 1998
 * In the Shadow of Descartes: Essays in the Philosophy of Mind, Dordrech, Kluwer, 1998
 * Mitt liv som jag minns det (My Life as I Remember it), in Swedish, 2001

Von Wright edited posthumous publications by Wittgenstein, which were published by Blackwell (unless otherwise stated):
 * 1961. Notebooks 1914-1916.
 * 1967. Zettel (Translated into English as Culture and Value).
 * 1969. On Certainty.
 * 1971. ProtoTractatus—An Early Version of Tractatus Logico-Philosophicus. Cornell University Press.
 * 1973. Letters to C. K. Ogden with Comments on the English Translation of the Tractatus Logico-Philosophicus.
 * 1974. Letters to Russell, Keynes and Moore.
 * 1978 (1956). Remarks on the Foundations of Mathematics.
 * 1980. Remarks on the Philosophy of Psychology, Vols 1–2.
 * 1980. Culture and Value (English translation of Zettel).
 * 1982. Last Writings on the Philosophy of Psychology, Vols. 1–2, 1992.

Von Wright also edited extracts from the diary of David Pinsent, also published by Wiley-Blackwell: * For more complete publication details see "Bibliography of the Writings of Georg Henrik von Wright" (in Schilpp, 1989) and "The Georg Henrik von Wright-Bibliography" (2005).
 * 1990.  A Portrait of Wittgenstein as a Young Man: From the Diary of David Hume Pinsent 1912–1914. ISBN 0-631-17511-3.

title: Georg Henrik von Wright


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Gaudy Night

Gaudy Night (1935) is a mystery novel by Dorothy L. Sayers, the tenth featuring Lord Peter Wimsey, and the third including Harriet Vane.

The dons of Harriet Vane's alma mater, the all-female Shrewsbury College, Oxford (based on Sayers' own Somerville College), have invited her back to attend the annual Gaudy celebrations. However, the mood turns sour when someone begins a series of malicious acts including poison-pen messages, obscene graffiti, and wanton vandalism. Despite the dons' reluctance to share the secret with an outsider, Harriet convinces them to let her bring in Lord Peter Wimsey to assist the investigation—but his involvement is not without complications, both personal and professional.

Plot
Harriet Vane returns with trepidation to her alma mater, Shrewsbury College, Oxford to attend the Gaudy dinner. Expecting hostility because of her notoriety (she had stood trial for murder in an earlier novel, Strong Poison), she is surprised to be welcomed warmly by most of the dons, and rediscovers her old love of academic life. Harriet's short stay is, however, marred by her discovery of a sheet of paper with an offensive drawing, and a poison pen message referring to her as a "dirty murderess".

Some time later the Dean of Shrewsbury writes to ask for her help. There has been an outbreak of vandalism and anonymous letters, and fearing for the college's reputation if this becomes public knowledge, the Dean wants someone to investigate confidentially. Harriet, herself a victim of poison-pen letters since her trial, reluctantly agrees, and returns to spend some months in residence, ostensibly to do research on Sheridan Le Fanu and to assist a don with her book. The timing of the first poison pen message during the gaudy, and the use of a Latin quotation from the Aeneid during one disturbance, focuses suspicion on the Senior Common Room dons, causing escalating tensions.

As Harriet wrestles with the case, trying to narrow down the list of suspects who might be responsible for poison-pen messages, obscene graffiti, wanton vandalism including the destruction of a set of scholarly proofs, and the crafting of vile effigies, she is forced to examine her ambivalent feelings about Wimsey, love and marriage, and her attraction to academia as an intellectual and emotional refuge. Wimsey eventually arrives in Oxford to help, and she gains a new perspective from those who know him, including his nephew, an undergraduate at the university.

The attacks build to a crisis. There is an attempt to drive a vulnerable student to suicide and a physical assault on Harriet that almost kills her. The perpetrator is finally unmasked as Annie Wilson, one of the college scouts, revealed to be the widow of a disgraced University of York academic. Her husband's academic fraud had been exposed by an examiner, destroying his career and driving him to suicide; his suicide note used the Latin quote eventually used by Wilson. The examiner later moved to Shrewsbury College, and the widow's campaign has been her revenge against the examiner in particular and more generally against intellectual women who move outside what she sees as their proper domestic sphere.

At the end of the book, with Wimsey admitting his own faults in his attempts at courtship and having come to terms with her own feelings, Harriet finally accepts Wimsey's proposal of marriage.

Principal characters

 * Harriet Vane – protagonist, a mystery writer
 * Lord Peter Wimsey – protagonist, an aristocratic amateur detective
 * Letitia Martin – Dean of Shrewsbury College
 * Helen de Vine – new Research Fellow at Shrewsbury College
 * Miss Lydgate – Harriet's former tutor
 * Dr Baring – Warden of Shrewsbury College
 * Miss Hillyard – history don at Shrewsbury College
 * Phoebe Tucker – Harriet's old college friend
 * Viscount Saint-George – Lord Peter's nephew, an undergraduate at Christ Church, Oxford
 * Reggie Pomfret – undergraduate at Queen's College
 * Miss Burrows – College librarian
 * Annie Wilson – scout at Shrewsbury College
 * Padgett – Head Porter at Shrewsbury College
 * Bunter – Lord Peter's manservant

Title
A "gaudy", at the University of Oxford, is a college feast, typically a reunion for its alumni. The term "gaudy night" appears in Shakespeare's Antony and Cleopatra: "Let's have one other gaudy night: call to me / All my sad captains; fill our bowls once more / Let's mock the midnight bell".

Literary significance and criticism
Writing in 1936, George Orwell disagreed with the opinion of an Observer critic who felt that Gaudy Night had put Miss Sayers "definitely among the great writers". Orwell concluded, to the contrary, that "her slickness in writing has blinded many readers to the fact that her stories, considered as detective stories, are very bad ones. They lack the minimum of probability that even a detective story ought to have, and the crime is always committed in a way that is incredibly tortuous and quite uninteresting".

Although no murder occurs in Gaudy Night, it includes a great deal of suspense and psychological thrills. The narrative is interwoven with a love story and an examination of women's struggles to enlarge their roles and achieve some independence within the social climate of 1930s England, and the novel has been described as "the first feminist mystery novel".

Jacques Barzun stated that "Gaudy Night is a remarkable achievement. Harriet Vane and Saint-George, the undergraduate nephew of Lord Peter, help give variety, and the college setting justifies good intellectual debate. The motive is magnificently orated on by the culprit in a scene that is a striking set-piece. And though the Shrewsbury dons are sometimes hard to distinguish one from another, the College architecture is very good".

Gaudy Night deals with a number of philosophical themes, such as the right relation between love and independence or between principles and personal loyalties. Susan Haack has an essay on Gaudy Night as a philosophical novel.

Women's education
The issue of women's right to academic education is central to the book's plot. The lecturers of Shrewsbury College are veterans of the prolonged struggle for academic degrees for women, which Oxford granted only reluctantly. The Fellows of the college are surprised and a bit dismayed at the attitude of their students, who take for granted this right for which such a hard struggle had to be fought.

Sayers had herself been one of the first women to obtain an Oxford University degree, having been awarded first-class honours in the mediaeval literature examinations of 1915. She attended Somerville College, the basis for the fictional Shrewsbury College of the plot.

Adaptations
The book was adapted as a three-part series for BBC television in 1987, starring Edward Petherbridge as Wimsey and Harriet Walter as Harriet.

In 2005 a dramatisation of the novel was released on CD by the BBC Radio Collection, with Joanna David as Harriet and Ian Carmichael as Wimsey, later broadcast on BBC Radio 7 in 2010.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Gaudy Night


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G

G, or g, is the seventh letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages, and others worldwide. Its name in English is gee (pronounced ), plural gees.

The lowercase version can be written in two forms: the single-storey (sometimes "opentail") and the double-storey (sometimes "looptail"). The former is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children.

History
The evolution of the Latin alphabet's G can be traced back to the Latin alphabet's predecessor, the Greek alphabet. The voiced velar stop was represented by the third letter of the Greek alphabet, gamma (Γ), which was later adopted by the Etruscan language. Latin then borrowed this "rounded form" of gamma, C, to represent the same sound in words such as recei, which was likely an early dative form of rex, meaning "king", as found in an "early Latin inscription." Over time, however, the letter C shifted to represent the unvoiced velar stop, leading to the displacement of the letter K. Scholars believe that this change can be attributed to the influence of the Etruscan language on Latin.

Afterwards, the letter 'G' was introduced in the Old Latin period as a variant of 'C' to distinguish voiced from voiceless, and G was used to represent a voiced velar from this point on and C "stood for the unvoiced velar only".

The recorded originator of 'G' is freedman Spurius Carvilius Ruga, who added letter G to the teaching of the Roman alphabet during the 3rd century BC: he was the first Roman to open a fee-paying school, around 230 BC. At this time, 'K' had fallen out of favor, and 'C', which had formerly represented both and  before open vowels, had come to express  in all environments.

Ruga's positioning of 'G' shows that alphabetic order related to the letters' values as Greek numerals was a concern even in the 3rd century BC. According to some records, the original seventh letter, 'Z', had been purged from the Latin alphabet somewhat earlier in the 3rd century BC by the Roman censor Appius Claudius, who found it distasteful and foreign. Sampson (1985) suggests that: "Evidently the order of the alphabet was felt to be such a concrete thing that a new letter could be added in the middle only if a 'space' was created by the dropping of an old letter."

George Hempl proposed in 1899 that there never was such a "space" in the alphabet and that in fact 'G' was a direct descendant of zeta. Zeta took shapes like ⊏ in some of the Old Italic scripts; the development of the monumental form 'G' from this shape would be exactly parallel to the development of 'C' from gamma. He suggests that the pronunciation >  was due to contamination from the also similar-looking 'K'.

Eventually, both velar consonants and  developed palatalized allophones before front vowels; consequently in today's Romance languages,  and  have different sound values depending on context (known as hard and soft C and hard and soft G). Because of French influence, English language orthography shares this feature.

Typographic variants
The modern lowercase g has two typographic variants: the single-storey (sometimes "opentail") and the double-storey (sometimes "looptail"). The single-storey form derives from the majuscule (uppercase) form by raising the serif that distinguishes it from 'c' to the top of the loop (thus closing the loop), and extending the vertical stroke downward and to the left. The double-storey form (Looptail g.svg) had developed similarly, except that some ornate forms then extended the tail back to the right, and to the left again, forming a closed bowl or loop. The initial extension to the left was absorbed into the upper closed bowl. The double-storey version became popular when printing switched from Blackletter type to Roman type, because the tail was effectively shorter, making it possible to put more lines on a page. In the double-storey version, a small top stroke in the upper-right, often terminating in an orb shape, is called an "ear".

Generally, the two forms are complementary and interchangeable; the form displayed is a typeface selection choice. In Unicode, the two appearances are generally treated as glyph variants with no semantic difference. Most serif typefaces use the looptail form (for example, g ) and most sans-serif typefaces use the opentail form (for example, g ) but the code point in both cases is U+0067. For applications where the single-storey variant must be distinguished (such as strict IPA in a typeface where the usual g character is double-storey), the character is available, as well as an upper case version,.

Occasionally the difference has been exploited to provide contrast. In the International Phonetic Alphabet, opentail $⟨Opentail g.svg⟩$ has always represented a voiced velar plosive, while looptail $⟨Looptail g.svg⟩$ represented a voiced velar fricative from 1895 to 1900. In 1948, the Council of the International Phonetic Association recognized ⟨ɡ⟩ and $⟨Looptail g.svg⟩$ as typographic equivalents, and this decision was reaffirmed in 1993. While the 1949 Principles of the International Phonetic Association recommended the use of $⟨Looptail g.svg⟩$ for a velar plosive and ⟨ɡ⟩ for an advanced one for languages where it is preferable to distinguish the two, such as Russian, this practice never caught on. The 1999 Handbook of the International Phonetic Association, the successor to the Principles, abandoned the recommendation and acknowledged both shapes as acceptable variants.

In 2018, a study found that native English speakers have little conscious awareness of the looptail form (Looptail g.svg). The authors write: "Despite being questioned repeatedly, and despite being informed directly that G has two lowercase print forms, nearly half of the participants failed to reveal any knowledge of the looptail 'g', and only 1 of the 38 participants was able to write looptail 'g' correctly".

English
In English, the letter appears either alone or in some digraphs. Alone, it represents
 * a voiced velar plosive ( or "hard" $⟨g⟩$), as in goose, gargoyle, and game;
 * a voiced palato-alveolar affricate ( or "soft" $⟨x⟩$), predominates before $⟨g⟩$ or $⟨g⟩$, as in giant, ginger, and geology; or
 * a voiced palato-alveolar sibilant in post-medieval loanwords from French, such as rouge, beige, genre (often), and margarine (rarely)

$⟨i⟩$ is predominantly soft before $⟨e⟩$ (including the digraphs $⟨g⟩$ and $⟨e⟩$), $⟨ae⟩$, or $⟨oe⟩$, and hard otherwise. It is hard in those derivations from γυνή (gynḗ) meaning woman where initial-worded as such. Soft $⟨i⟩$ is also used in many words that came into English from medieval church/academic use, French, Spanish, Italian or Portuguese – these tend to, in other ways in English, closely align to their Ancient Latin and Greek roots (such as fragile, logic or magic). There remain widely used a few English words of non-Romance origin where $⟨y⟩$ is hard followed by $⟨g⟩$ or $⟨g⟩$ (get, give, gift), and very few in which $⟨e⟩$ is soft though followed by $⟨i⟩$ such as gaol, which since the 20th century is almost always written as "jail".

The double consonant $⟨g⟩$ has the value (hard $⟨a⟩$) as in nugget, with very few exceptions:  in exaggerate and veggies and dialectally  in suggest.

The digraph $⟨gg⟩$ has the value (soft $⟨g⟩$), as in badger. Non-digraph $⟨dg⟩$ can also occur, in compounds like floodgate and headgear.

The digraph $⟨g⟩$ may represent: Non-digraph $⟨dg⟩$ also occurs, with possible values
 * a velar nasal as in length, singer
 * the latter followed by hard $⟨ng⟩$ as in jungle, finger, longest
 * as in engulf, ungainly
 * as in sponge, angel
 * as in melange

The digraph $⟨g⟩$ (in many cases a replacement for the obsolete letter yogh, which took various values including, , and ) may represent: Non-digraph $⟨ng⟩$ also occurs, in compounds like foghorn, pigheaded.
 * as in ghost, aghast, burgher, spaghetti
 * as in cough, laugh, roughage
 * ∅ (no sound) as in through, neighbor, night
 * in ugh
 * (rarely) in hiccough
 * (rarely) in s'ghetti

The digraph $⟨gh⟩$ may represent: Non-digraph $⟨gh⟩$ also occurs, as in signature, agnostic.
 * as in gnostic, deign, foreigner, signage
 * in loanwords like champignon, lasagna

The trigraph $⟨gn⟩$ has the value as in gingham or dinghy. Non-trigraph $⟨gn⟩$ also occurs, in compounds like stronghold and dunghill.

G is the tenth least frequently used letter in the English language (after Y, P, B, V, K, J, X, Q, and Z), with a frequency of about 2.02% in words.

Other languages
Most Romance languages and some Nordic languages also have two main pronunciations for $⟨ngh⟩$, hard and soft. While the soft value of $⟨ngh⟩$ varies in different Romance languages ( in French and Portuguese, in Catalan,  in Italian and Romanian, and  in most dialects of Spanish), in all except Romanian and Italian, soft $⟨g⟩$ has the same pronunciation as the $⟨g⟩$.

In Italian and Romanian, $⟨g⟩$ is used to represent before front vowels where $⟨j⟩$ would otherwise represent a soft value. In Italian and French, $⟨gh⟩$ is used to represent the palatal nasal, a sound somewhat similar to the $⟨g⟩$ in English canyon. In Italian, the trigraph $⟨gn⟩$, when appearing before a vowel or as the article and pronoun gli, represents the palatal lateral approximant. Other languages typically use $⟨ny⟩$ to represent, regardless of position.

Amongst European languages, Czech, Dutch, Estonian and Finnish are exceptions, as they do not have in their native words. In Dutch, $⟨gli⟩$ represents a voiced velar fricative instead, a sound that does not occur in modern English, but there is a dialectal variation: many Netherlandic dialects use a voiceless fricative ( or ) instead, and in southern dialects it may be palatal. Nevertheless, word-finally, it is always voiceless in all dialects, including the standard Dutch of Belgium and the Netherlands. On the other hand, some dialects (like Amelands) may have a phonemic.

Faroese uses $⟨g⟩$ to represent, in addition to , and also uses it to indicate a glide.

In Māori, $⟨g⟩$ is used in the digraph $⟨g⟩$ which represents the velar nasal and is pronounced like the $⟨g⟩$ in singer.

The Samoan and Fijian languages use the letter $⟨ng⟩$ by itself for.

In older Czech and Slovak orthographies, $⟨ng⟩$ was used to represent, while was written as $⟨g⟩$ ($⟨g⟩$ with caron).

The Azerbaijani Latin alphabet uses $⟨ǧ⟩$ exclusively for the "soft" sound, namely. The sound is written as $⟨g⟩$. This leads to unusual spellings of loanwords: qram 'gram', qrup 'group', qaraj 'garage', qallium 'gallium'.

Other systems
In the International Phonetic Alphabet, $⟨g⟩$ represents the voiced velar plosive. The small caps $⟨q⟩$ represents the voiced uvular plosive.

Other uses

 * Unit prefix G, meaning 1,000,000,000 times.

Ancestors, descendants and siblings

 * 𐤂 : Semitic letter Gimel, from which the following symbols originally derive
 * C c : Latin letter C, from which G derives
 * Γ γ : Greek letter Gamma, from which C derives in turn
 * ɡ : Latin letter ɡ|script small G
 * ᶢ : Modifier letter small script g is used for phonetic transcription
 * 𝼁 : Latin small letter reversed script g, an extension to IPA for disordered speech (extIPA)
 * ᵷ : Turned g
 * 𝼂 : Latin letter small capital turned g, an extension to IPA for disordered speech (extIPA)
 * Г г : Cyrillic letter Ge
 * Ȝ ȝ : Latin letter Ȝ|Yogh
 * Ɣ ɣ : Latin letter Gamma
 * Ᵹ ᵹ : Insular g
 * ᫌ : Combining insular g, used in the Ormulum
 * Ꝿ ꝿ : Turned insular g
 * Ꟑ ꟑ : Closed insular g, used in the Ormulum
 * ɢ : Latin letter small capital G, used in the International Phonetic Alphabet to represent a voiced uvular stop
 * 𐞒 : Modifier letter small capital G, used as a superscript IPA letter
 * ʛ : Latin letter small capital G with hook, used in the International Phonetic Alphabet to represent a voiced uvular implosive
 * 𐞔 : Modifier letter small capital G with hook, used as a superscript IPA letter
 * 𐞓 : Modifier letter small g with hook, used as a superscript IPA letter
 * ᴳ ᵍ : Modifier letters are used in the Uralic Phonetic Alphabet
 * ꬶ : Used for the Teuthonista phonetic transcription system
 * G with diacritics: Ǵ|Ǵ ǵ Ǥ ǥ Ĝ|Ĝ ĝ Ǧ|Ǧ ǧ Ğ|Ğ ğ Ģ ģ Ɠ|Ɠ ɠ Ġ|Ġ ġ Ḡ|Ḡ ḡ Ꞡ|Ꞡ ꞡ ᶃ
 * ց : Armenian alphabet Tso

Ligatures and abbreviations

 * ₲ : Paraguayan guaraní
 * ㎏ : the kilogram symbol as a single character in the CJK Compatibility block

Computing

 * 1 Also for encodings based on ASCII, including the DOS, Windows, ISO-8859 and Macintosh families of encodings.

title: G


text:
Gamma

Gamma (uppercase, lowercase ; γάμμα) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop. In Modern Greek, this letter normally represents a voiced velar fricative, except before either of the two front vowels (/e/, /i/), where it represents a voiced palatal fricative ; while /g/ in foreign words is instead commonly transcribed as γκ).

In the International Phonetic Alphabet and other modern Latin-alphabet based phonetic notations, it represents the voiced velar fricative.

History
The Greek letter Gamma Γ is a grapheme derived from the Phoenician letter (gīml) which was rotated from the right-to-left script of Canaanite to accommodate the Greek language's writing system of left-to-right. The Canaanite grapheme represented the /g/ phoneme in the Canaanite language, and as such is cognate with gimel ג of the Hebrew alphabet.

Based on its name, the letter has been interpreted as an abstract representation of a camel's neck, but this has been criticized as contrived, and it is more likely that the letter is derived from an Egyptian hieroglyph representing a club or throwing stick.

In Archaic Greece, the shape of gamma was closer to a classical lambda (Λ), while lambda retained the Phoenician L-shape.

Letters that arose from the Greek gamma include Etruscan (Old Italic) 𐌂, Roman C and G, Runic kaunan, Gothic geuua , the Coptic Ⲅ, and the Cyrillic letters Г and Ґ.

Greek phoneme
The Ancient Greek /g/ phoneme was the voiced velar stop, continuing the reconstructed proto-Indo-European *g, *ǵ.

The modern Greek phoneme represented by gamma is realized either as a voiced palatal fricative before a front vowel (/e/, /i/), or as a voiced velar fricative  in all other environments. Both in Ancient and in Modern Greek, before other velar consonants (κ, χ, ξ – that is, k, kh, ks), gamma represents a velar nasal. A double gamma γγ (e.g., άγγελος, "angel") represents the sequence (phonetically varying ) or.

Phonetic transcription
Lowercase Greek gamma is used in the Americanist phonetic notation and Uralic Phonetic Alphabet to indicate voiced consonants.

The gamma was also added to the Latin alphabet, as Latin gamma, in the following forms: majuscule Ɣ, minuscule ɣ, and superscript modifier letter ˠ.

In the International Phonetic Alphabet the minuscule letter is used to represent a voiced velar fricative and the superscript modifier letter is used to represent velarization. It is not to be confused with the character, which looks like a lowercase Latin gamma that lies above the baseline rather than crossing, and which represents the close-mid back unrounded vowel. In certain nonstandard variations of the IPA, the uppercase form is used.

It is as a full-fledged majuscule and minuscule letter in the alphabets of some of languages of Africa such as Dagbani, Dinka, Kabye, and Ewe, and Berber languages using the Berber Latin alphabet.

It is sometimes also used in the romanization of Pashto.

Lowercase
The lowercase letter $$\gamma$$ is used as a symbol for:
 * Chromatic number of in graph theory
 * Gamma radiation in nuclear physics
 * The photon, the elementary particle of light and other electromagnetic radiation
 * The 434 nm spectral line in the Balmer series
 * Surface energy in materials science
 * The Lorentz factor in the theory of relativity
 * In mathematics, the lower incomplete gamma function
 * The Euler–Mascheroni constant ≈ 0.57721566490153286
 * The heat capacity ratio Cp  /Cv in thermodynamics
 * The activity coefficient in thermodynamics
 * The gyromagnetic ratio in electromagnetism
 * Gamma waves in neuroscience
 * Gamma motor neurons in neuroscience
 * A non-SI metric unit of measure of mass equal to one microgram (1 μg). This always-rare use is deprecated.
 * A non-SI unit of measure of magnetic flux density, sometimes used in geophysics, equal to 10−5 Gauss (G), or 1 nanotesla (nT).
 * The power by which the luminance of an image is increased in gamma correction
 * In civil and mechanical engineering:
 * Specific weight
 * The shear rate of a fluid is represented by a lowercase gamma with a dot above it: $$ \dot \gamma $$
 * Austenite (also known as γ-iron), a metallic non-magnetic allotrope or solid solution of iron.
 * The gamma carbon, the third carbon attached to a functional group in organic chemistry and biochemistry; see Alpha and beta carbon

The lowercase Latin gamma ɣ can also be used in contexts (such as chemical or molecule nomenclature) where gamma must not be confused with the letter y, which can occur in some computer typefaces.

Uppercase
The uppercase letter $$\Gamma$$ is used as a symbol for:
 * In mathematics, the gamma function (usually written as $$\Gamma$$-function) is an extension of the factorial to complex numbers
 * In mathematics, the upper incomplete gamma function
 * The Christoffel symbols in differential geometry
 * In probability theory and statistics, the gamma distribution is a two-parameter family of continuous probability distributions.
 * In solid-state physics, the center of the Brillouin zone
 * Circulation in fluid mechanics
 * As reflection coefficient in physics and electrical engineering
 * The tape alphabet of a Turing machine
 * The Feferman–Schütte ordinal $$\Gamma_0$$
 * One of the Greeks in mathematical finance

HTML
The HTML entities for uppercase and lowercase gamma are  and.

Unicode

 * Greek Gamma

 * Coptic Gamma

 * Latin Gamma / phonetic Gamma

 * CJK Square Gamma

 * Technical / Mathematical Gamma

These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.

title: Gamma


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Talk:Guglielmo Marconi

Menace quote
"Have I done the world good, or have I added a menace?" According to the referenced source, it's speculated that this quote expresses Marconi's regret that his invention was used in WW1. So, I moved the quote down a bit to be in the more relevant section. Although his invention's role in WW1 is somewhat obvious, the article could be improved with specific examples of use, impacts on the outcome, casualties, tactics, etc. It would also help to show any other similar statements of regret from Marconi that might be more direct or elaborate, if any exist. 2600:1700:C7F0:5510:813:BABB:2FC1:9B97 (talk) 02:24, 27 August 2018 (UTC)

The official inventor of Radio is considered to be Tesla not Marconi
Nikola Tesla is considered to be the inventor of Radio, US patent no. 645,576, System of transmission of electrical energy. https://patents.google.com/patent/US645576A/en --AlexanderFreud (talk) 15:27, 30 January 2019 (UTC)
 * A patent is not a secondary source. Please see above for previous discussion on this issue. PearlSt82 (talk) 16:02, 30 January 2019 (UTC)
 * How can a registered Patent not be a source when we are discussing about the paternity of such patent?!? --AlexanderFreud (talk) 10:42, 9 September 2019 (UTC)
 * A patent is a primary source. We need secondary sources. PearlSt82 (talk) 20:36, 9 September 2019 (UTC)
 * Tesla’s system to transmit energy-not signals- was a crazy ad unfeasible network of balloons stations in the air above 30,000 feet (9,100 m) in altitude, where he thought the lower pressure would allow him to send high voltages (millions of volts) long distances.
 * Tesla proposed using huge transformers to blast "electrical impulses of sufficiently-high electromotive force to render elevated air strata conducting, causing, thereby current impulses to pass, by conduction, through the air strata".

 * The patent specifies massive voltages, starting at 20 to 50 million volts, in order to propel currents via "natural media" conduction.
 * In addition, he continued to stress that his system did not use radio waves (electromagnetic radiation), which he considered a useless waste product, akin to heat, to be suppressed as much as possible -- "Apart from the transmitting and receiving apparatus the only loss incurred is the energy radiated in the form of Hertzian or electro-magnetic waves which can be reduced to an entirely insignificant quantity."Magnagr (talk) 02:08, 24 February 2019 (UTC)
 * US government recognised Radio patent to Tesla post mortem of both Marconi and Tesla; since you-Wikipedians need sources here you have two (I could provide more in case): Margaret CHENEY Tesla · Man Out of Time, Touchstone, USA, 1981 Tesla · Man Out of Time. Müzej Nikole Tesle, Beograd, Serbia (Nikola Tesla Museum). I have been visiting twice Nikola Tesla Museum in Belgrade, an institution which has been established in 1952 and present-day annually host some 135,000 visitors; the museum guide told me Guglielmo Marconi actually 'stole' 7 patents from Nikola Tesla. As an Italian I would have at least a nationalism reason in consider Marconi as the inventor of Radio; as an Historian of Science as I am I would consider many people contributed to the invention of Radio; Tesla is among them; Marconi basically did the effort to get financial support and take commercial/militar advantage from it. --AlexanderFreud (talk) 10:42, 9 September 2019 (UTC)
 * You've only posted one source here, "Man out of Time", what a tourguide told you personally isn't a source. If you want to make a claim based on that book, please post relevant sections of the text. The US government did not recognize Tesla as the inventor of radio. The US Supreme court decision deals more with John Stone Stone and Oliver Lodge's patents rather than Tesla's. PearlSt82 (talk) 20:36, 9 September 2019 (UTC)
 * As an Italian you would know that the US Supreme Court has no power over patents in your country, especially in 1943. Marconi's 1897 UK patent remains the first and original patent on radio and was the one recognised in Italy.
 * The US isn't the world. Marconi's 1897 patent predates Tesla by 3 years. For what it's worth the oldest radio patent is Marconi's 1897 patent. https://patents.google.com/patent/GB189612039A/en Vk2dy (talk) 10:09, 8 March 2024 (UTC)

Sir Jagadis Chandra Bose
Sir Jagadis Chandra Bose

In November 1894, the Indian physicist, Jagadish Chandra Bose, demonstrated publicly the use of radio waves in Calcutta.--2003:F2:8701:E664:2469:FC97:11E1:8C1C (talk) 19:25, 7 August 2021 (UTC)

 * Lodge did it before him (Jagadish Chandra Bose), and neither were interested in radio communication. Fountains of Bryn Mawr (talk) 21:54, 7 August 2021 (UTC)

JC Bose didn't invented radio but discovered radio waves Obiwana (talk) 10:23, 15 January 2023 (UTC)

Additional book title to be added to the list for further reading:
"Marconi's Wireless Telegraph Stations in Essex - The Centenary of Brentwood and Ongar Radio Stations" ISBN 978-180369-3828 by Paul M. Hawkins and Paul G. Reyland - pub.2022 by New Generation Publishing.

100 Years ago Marconi was busy setting up wireless telegraphy links between the UK and countries across the world. After WW1 valve technology enabled station to be built near London and hence two site near the Marconi factory in Chelmsford were chosen. This is the story of the receiving station at Brentwood and transmitting station at Ongar commencing operation in 1921 and operating throughout the period when LF and HF radio dominated international telecommunications. 2A00:23C6:B62F:4501:D56E:7426:5C2A:B21A (talk) 20:14, 17 April 2023 (UTC)
 * According to their website, New Generation Publishing is a "self-publishing service dedicated to helping more writers to sell more books". Per WP:SPS I would argue this should not be included, as there is already a huge volume of work on Marconi.PearlSt82 (talk) 20:19, 17 April 2023 (UTC)

Apologist for Fascist Idiology
I am curious about the statement that "Marconi was an apologist for Fascist idiology and actions such as the Italian invasion of Ethiopia in the Second Italo-Abyssinian War". Describing him as an "apologist" creates the impression that he wrote articles or gave speeches defending Fascist idiology, but this does not seem to have been the case. The only reference given to support the statement is to a 1935 article in the NYT about his brief announcement that he was joining the invasion of Ethiopia, presumably to coordinate communications services. There is no information about his motives for volunteering, whether it was his personal political views, a sense of loyalty to his country, or a desire to mess around with radio gear at government expense. Should we trim this statement back to what is actually known from the sources? Chappell (talk) 18:48, 2 January 2024 (UTC)

title: Talk:Guglielmo Marconi


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Goitre

A goitre, or goiter, is a swelling in the neck resulting from an enlarged thyroid gland. A goitre can be associated with a thyroid that is not functioning properly.

Worldwide, over 90% of goitre cases are caused by iodine deficiency. The term is from the Latin gutturia, meaning throat. Most goitres are not cancerous (benign), though they may be potentially harmful.

Signs and symptoms
A goitre can present as a palpable or visible enlargement of the thyroid gland at the base of the neck. A goitre, if associated with hypothyroidism or hyperthyroidism, may be present with symptoms of the underlying disorder. For hyperthyroidism, the most common symptoms are associated with adrenergic stimulation: tachycardia (increased heart rate), palpitations, nervousness, tremor, increased blood pressure and heat intolerance. Clinical manifestations are often related to hypermetabolism (increased metabolism), excessive thyroid hormone, an increase in oxygen consumption, metabolic changes in protein metabolism, immunologic stimulation of diffuse goitre, and ocular changes (exophthalmos). Hypothyroid people commonly have poor appetite, cold intolerance, constipation, lethargy and may undergo weight gain. However, these symptoms are often non-specific and make diagnosis difficult.

According to the WHO classification of goitre by palpation, the severity of goitre is currently graded as grade 0, grade 1, grade 2.

Causes
Worldwide, the most common cause for goitre is iodine deficiency, commonly seen in countries that scarcely use iodized salt. Selenium deficiency is also considered a contributing factor. In countries that use iodized salt, Hashimoto's thyroiditis is the most common cause. Goitre can also result from cyanide poisoning, which is particularly common in tropical countries where people eat the cyanide-rich cassava root as the staple food.

 * Sarcoidosis
 * Amyloidosis
 * Hydatidiform mole
 * Cysts
 * Acromegaly
 * Pendred syndrome

Diagnosis
Goitre may be diagnosed via a thyroid function test in an individual suspected of having it.

Types
A goitre may be classified either as nodular or diffuse. Nodular goitres are either of one nodule (uninodular) or of multiple nodules (multinodular). Multinodular goiter (MNG) is the most common disorder of the thyroid gland.

 * Growth pattern:
 * Uninodular goitre: one thyroid nodule; can be either inactive, or active (toxic) – autonomously producing thyroid hormone.
 * Multinodular goitre: multiple nodules; can likewise be inactive or toxic, the latter is called toxic multinodular goitre and associated with hyperthyroidism. These nodules grow up at varying rates and secrete thyroid hormone autonomously, thereby suppressing TSH-dependent growth and function in the rest of gland. Inactive nodules in the same goitre can be malignant. Thyroid cancer is identified in 13.7% of the patients operated for multinodular goitre.
 * Diffuse goitre: the whole thyroid appearing to be enlarged due to hyperplasia.

 * Size:
 * Class I: the goitre in normal posture of the head cannot be seen; it is only found by palpation.
 * Class II: the goitre is palpable and can be easily seen.
 * Class III: the goitre is very large and is retrosternal (partially or totally lying below the sternum), pressure results in compression marks.

Treatment
Goitre is treated according to the cause. If the thyroid gland is producing an excess of thyroid hormones (T3 and T4), radioactive iodine is given to the patient to shrink the gland. If goitre is caused by iodine deficiency, small doses of iodide in the form of Lugol's iodine or KI solution are given. If the goitre is associated with an underactive thyroid, thyroid supplements are used as treatment. Sometimes a partial or complete thyroidectomy is required.

Epidemiology
Goitre is more common among women, but this includes the many types of goitre caused by autoimmune problems, and not only those caused by simple lack of iodine.

Iodine mainly accumulates in the sea and in the topsoil. Before iodine enrichment programs, goiters were common in areas with repeated flooding or glacial activities, which erodes the topsoil. It is endemic in populations where the intake of iodine is less than 10 μg per day.

Examples of such regions include the alpine regions of Southern Europe (such as Switzerland), the Himalayans, the Great Lakes basin, etc. As reported in 1923, all the domestic animals have goiter in some of the glacial valleys of Southern Alaska. It was so severe in Pemberton Meadows that it was difficult to raise young animals there.

History
Chinese physicians of the Tang dynasty (618–907) were the first to successfully treat patients with goitre by using the iodine-rich thyroid gland of animals such as sheep and pigs—in raw, pill, or powdered form. This was outlined in Zhen Quan's (d. 643 AD) book, as well as several others. One Chinese book, The Pharmacopoeia of the Heavenly Husbandman, asserted that iodine-rich sargassum was used to treat goitre patients by the 1st century BC, but this book was written much later.

In the 12th century, Zayn al-Din al-Jurjani, a Persian physician, provided the first description of Graves' disease after noting the association of goitre and a displacement of the eye known as exophthalmos in his Thesaurus of the Shah of Khwarazm, the major medical dictionary of its time. The disease was later named after Irish doctor Robert James Graves, who described a case of goitre with exophthalmos in 1835. The German Karl Adolph von Basedow also independently reported the same constellation of symptoms in 1840, while earlier reports of the disease were also published by the Italians Giuseppe Flajani and Antonio Giuseppe Testa, in 1802 and 1810 respectively, and by the English physician Caleb Hillier Parry (a friend of Edward Jenner) in the late 18th century.

Paracelsus (1493–1541) was the first person to propose a relationship between goitre and minerals (particularly lead) in drinking water. Iodine was later discovered by Bernard Courtois in 1811 from seaweed ash.

Goitre was previously common in many areas that were deficient in iodine in the soil. For example, in the English Midlands, the condition was known as Derbyshire Neck. In the United States, goitre was found in the Appalachian, Great Lakes, Midwest, and Intermountain regions. The condition is now practically absent in affluent nations, where table salt is supplemented with iodine. However, it is still prevalent in India, China, Central Asia, and Central Africa.

Goitre had been prevalent in the alpine countries for a long time. Switzerland reduced the condition by introducing iodized salt in 1922. The Bavarian tracht in the Miesbach and Salzburg regions, which appeared in the 19th century, includes a choker, dubbed Kropfband (struma band) which was used to hide either the goitre or the remnants of goitre surgery.

Society and culture
In the 1920s wearing bottles of iodine around the neck was believed to prevent goitre.

Notable cases

 * Former U.S. President George H. W. Bush and his wife Barbara Bush were both diagnosed with Graves' disease and goitres, within two years of each other. The disease caused hyperthyroidism and cardiac dysrhythmia.  Scientists said that, absent an environmental cause, the odds of both a husband and wife having Graves' disease might be 1 in 100,000 or as low as 1 in 3,000,000.

Heraldry
The coat of arms and crest of Die Kröpfner, of Tyrol showed a man "afflicted with a large goitre", an apparent pun on the German for the word ("Kropf").

title: Goitre


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Genetics

Genetics is the study of genes, genetic variation, and heredity in organisms. It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene.

Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the context of a population. Genetics has given rise to a number of subfields, including molecular genetics, epigenetics, and population genetics. Organisms studied within the broad field span the domains of life (archaea, bacteria, and eukarya).

Genetic processes work in combination with an organism's environment and experiences to influence development and behavior, often referred to as nature versus nurture. The intracellular or extracellular environment of a living cell or organism may increase or decrease gene transcription. A classic example is two seeds of genetically identical corn, one placed in a temperate climate and one in an arid climate (lacking sufficient waterfall or rain). While the average height of the two corn stalks may be genetically determined to be equal, the one in the arid climate only grows to half the height of the one in the temperate climate due to lack of water and nutrients in its environment.

Etymology
The word genetics stems from the ancient Greek γενετικός genetikos meaning "genitive"/"generative", which in turn derives from γένεσις genesis meaning "origin".

History
The observation that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding. The modern science of genetics, seeking to understand this process, began with the work of the Augustinian friar Gregor Mendel in the mid-19th century. Prior to Mendel, Imre Festetics, a Hungarian noble, who lived in Kőszeg before Mendel, was the first who used the word "genetic" in hereditarian context, and is considered the first geneticist. He described several rules of biological inheritance in his work The genetic laws of nature (Die genetischen Gesetze der Natur, 1819). His second law is the same as that which Mendel published. In his third law, he developed the basic principles of mutation (he can be considered a forerunner of Hugo de Vries). Festetics argued that changes observed in the generation of farm animals, plants, and humans are the result of scientific laws. Festetics empirically deduced that organisms inherit their characteristics, not acquire them. He recognized recessive traits and inherent variation by postulating that traits of past generations could reappear later, and organisms could produce progeny with different attributes. These observations represent an important prelude to Mendel's theory of particulate inheritance insofar as it features a transition of heredity from its status as myth to that of a scientific discipline, by providing a fundamental theoretical basis for genetics in the twentieth century.

Other theories of inheritance preceded Mendel's work. A popular theory during the 19th century, and implied by Charles Darwin's 1859 On the Origin of Species, was blending inheritance: the idea that individuals inherit a smooth blend of traits from their parents. Mendel's work provided examples where traits were definitely not blended after hybridization, showing that traits are produced by combinations of distinct genes rather than a continuous blend. Blending of traits in the progeny is now explained by the action of multiple genes with quantitative effects. Another theory that had some support at that time was the inheritance of acquired characteristics: the belief that individuals inherit traits strengthened by their parents. This theory (commonly associated with Jean-Baptiste Lamarck) is now known to be wrong—the experiences of individuals do not affect the genes they pass to their children. Other theories included Darwin's pangenesis (which had both acquired and inherited aspects) and Francis Galton's reformulation of pangenesis as both particulate and inherited.

Mendelian genetics

Modern genetics started with Mendel's studies of the nature of inheritance in plants. In his paper "Versuche über Pflanzenhybriden" ("Experiments on Plant Hybridization"), presented in 1865 to the Naturforschender Verein (Society for Research in Nature) in Brno, Mendel traced the inheritance patterns of certain traits in pea plants and described them mathematically. Although this pattern of inheritance could only be observed for a few traits, Mendel's work suggested that heredity was particulate, not acquired, and that the inheritance patterns of many traits could be explained through simple rules and ratios.

The importance of Mendel's work did not gain wide understanding until 1900, after his death, when Hugo de Vries and other scientists rediscovered his research. William Bateson, a proponent of Mendel's work, coined the word genetics in 1905. (The adjective genetic, derived from the Greek word genesis—γένεσις, "origin", predates the noun and was first used in a biological sense in 1860.) Bateson both acted as a mentor and was aided significantly by the work of other scientists from Newnham College at Cambridge, specifically the work of Becky Saunders, Nora Darwin Barlow, and Muriel Wheldale Onslow. Bateson popularized the usage of the word genetics to describe the study of inheritance in his inaugural address to the Third International Conference on Plant Hybridization in London in 1906.

After the rediscovery of Mendel's work, scientists tried to determine which molecules in the cell were responsible for inheritance. In 1900, Nettie Stevens began studying the mealworm. Over the next 11 years, she discovered that females only had the X chromosome and males had both X and Y chromosomes. She was able to conclude that sex is a chromosomal factor and is determined by the male. In 1911, Thomas Hunt Morgan argued that genes are on chromosomes, based on observations of a sex-linked white eye mutation in fruit flies. In 1913, his student Alfred Sturtevant used the phenomenon of genetic linkage to show that genes are arranged linearly on the chromosome.

Molecular genetics

Although genes were known to exist on chromosomes, chromosomes are composed of both protein and DNA, and scientists did not know which of the two is responsible for inheritance. In 1928, Frederick Griffith discovered the phenomenon of transformation: dead bacteria could transfer genetic material to "transform" other still-living bacteria. Sixteen years later, in 1944, the Avery–MacLeod–McCarty experiment identified DNA as the molecule responsible for transformation. The role of the nucleus as the repository of genetic information in eukaryotes had been established by Hämmerling in 1943 in his work on the single celled alga Acetabularia. The Hershey–Chase experiment in 1952 confirmed that DNA (rather than protein) is the genetic material of the viruses that infect bacteria, providing further evidence that DNA is the molecule responsible for inheritance.

James Watson and Francis Crick determined the structure of DNA in 1953, using the X-ray crystallography work of Rosalind Franklin and Maurice Wilkins that indicated DNA has a helical structure (i.e., shaped like a corkscrew). Their double-helix model had two strands of DNA with the nucleotides pointing inward, each matching a complementary nucleotide on the other strand to form what look like rungs on a twisted ladder. This structure showed that genetic information exists in the sequence of nucleotides on each strand of DNA. The structure also suggested a simple method for replication: if the strands are separated, new partner strands can be reconstructed for each based on the sequence of the old strand. This property is what gives DNA its semi-conservative nature where one strand of new DNA is from an original parent strand.

Although the structure of DNA showed how inheritance works, it was still not known how DNA influences the behavior of cells. In the following years, scientists tried to understand how DNA controls the process of protein production. It was discovered that the cell uses DNA as a template to create matching messenger RNA, molecules with nucleotides very similar to DNA. The nucleotide sequence of a messenger RNA is used to create an amino acid sequence in protein; this translation between nucleotide sequences and amino acid sequences is known as the genetic code.

With the newfound molecular understanding of inheritance came an explosion of research. A notable theory arose from Tomoko Ohta in 1973 with her amendment to the neutral theory of molecular evolution through publishing the nearly neutral theory of molecular evolution. In this theory, Ohta stressed the importance of natural selection and the environment to the rate at which genetic evolution occurs. One important development was chain-termination DNA sequencing in 1977 by Frederick Sanger. This technology allows scientists to read the nucleotide sequence of a DNA molecule. In 1983, Kary Banks Mullis developed the polymerase chain reaction, providing a quick way to isolate and amplify a specific section of DNA from a mixture. The efforts of the Human Genome Project, Department of Energy, NIH, and parallel private efforts by Celera Genomics led to the sequencing of the human genome in 2003.

Discrete inheritance and Mendel's laws
At its most fundamental level, inheritance in organisms occurs by passing discrete heritable units, called genes, from parents to offspring. This property was first observed by Gregor Mendel, who studied the segregation of heritable traits in pea plants, showing for example that flowers on a single plant were either purple or white—but never an intermediate between the two colors. The discrete versions of the same gene controlling the inherited appearance (phenotypes) are called alleles.

In the case of the pea, which is a diploid species, each individual plant has two copies of each gene, one copy inherited from each parent. Many species, including humans, have this pattern of inheritance. Diploid organisms with two copies of the same allele of a given gene are called homozygous at that gene locus, while organisms with two different alleles of a given gene are called heterozygous. The set of alleles for a given organism is called its genotype, while the observable traits of the organism are called its phenotype. When organisms are heterozygous at a gene, often one allele is called dominant as its qualities dominate the phenotype of the organism, while the other allele is called recessive as its qualities recede and are not observed. Some alleles do not have complete dominance and instead have incomplete dominance by expressing an intermediate phenotype, or codominance by expressing both alleles at once.

When a pair of organisms reproduce sexually, their offspring randomly inherit one of the two alleles from each parent. These observations of discrete inheritance and the segregation of alleles are collectively known as Mendel's first law or the Law of Segregation. However, the probability of getting one gene over the other can change due to dominant, recessive, homozygous, or heterozygous genes. For example, Mendel found that if you cross heterozygous organisms your odds of getting the dominant trait is 3:1. Real geneticist study and calculate probabilities by using theoretical probabilities, empirical probabilities, the product rule, the sum rule, and more.

Notation and diagrams

Geneticists use diagrams and symbols to describe inheritance. A gene is represented by one or a few letters. Often a "+" symbol is used to mark the usual, non-mutant allele for a gene.

In fertilization and breeding experiments (and especially when discussing Mendel's laws) the parents are referred to as the "P" generation and the offspring as the "F1" (first filial) generation. When the F1 offspring mate with each other, the offspring are called the "F2" (second filial) generation. One of the common diagrams used to predict the result of cross-breeding is the Punnett square.

When studying human genetic diseases, geneticists often use pedigree charts to represent the inheritance of traits. These charts map the inheritance of a trait in a family tree.

Multiple gene interactions

Organisms have thousands of genes, and in sexually reproducing organisms these genes generally assort independently of each other. This means that the inheritance of an allele for yellow or green pea color is unrelated to the inheritance of alleles for white or purple flowers. This phenomenon, known as "Mendel's second law" or the "law of independent assortment," means that the alleles of different genes get shuffled between parents to form offspring with many different combinations. Different genes often interact to influence the same trait. In the Blue-eyed Mary (Omphalodes verna), for example, there exists a gene with alleles that determine the color of flowers: blue or magenta. Another gene, however, controls whether the flowers have color at all or are white. When a plant has two copies of this white allele, its flowers are white—regardless of whether the first gene has blue or magenta alleles. This interaction between genes is called epistasis, with the second gene epistatic to the first.

Many traits are not discrete features (e.g. purple or white flowers) but are instead continuous features (e.g. human height and skin color). These complex traits are products of many genes. The influence of these genes is mediated, to varying degrees, by the environment an organism has experienced. The degree to which an organism's genes contribute to a complex trait is called heritability. Measurement of the heritability of a trait is relative—in a more variable environment, the environment has a bigger influence on the total variation of the trait. For example, human height is a trait with complex causes. It has a heritability of 89% in the United States. In Nigeria, however, where people experience a more variable access to good nutrition and health care, height has a heritability of only 62%.

DNA and chromosomes
The molecular basis for genes is deoxyribonucleic acid (DNA). DNA is composed of deoxyribose (sugar molecule), a phosphate group, and a base (amine group). There are four types of bases: adenine (A), cytosine (C), guanine (G), and thymine (T). The phosphates make hydrogen bonds with the sugars to make long phosphate-sugar backbones. Bases specifically pair together (T&A, C&G) between two backbones and make like rungs on a ladder. The bases, phosphates, and sugars together make a nucleotide that connects to make long chains of DNA. Genetic information exists in the sequence of these nucleotides, and genes exist as stretches of sequence along the DNA chain. These chains coil into a double a-helix structure and wrap around proteins called Histones which provide the structural support. DNA wrapped around these histones are called chromosomes. Viruses sometimes use the similar molecule RNA instead of DNA as their genetic material.

DNA normally exists as a double-stranded molecule, coiled into the shape of a double helix. Each nucleotide in DNA preferentially pairs with its partner nucleotide on the opposite strand: A pairs with T, and C pairs with G. Thus, in its two-stranded form, each strand effectively contains all necessary information, redundant with its partner strand. This structure of DNA is the physical basis for inheritance: DNA replication duplicates the genetic information by splitting the strands and using each strand as a template for synthesis of a new partner strand.

Genes are arranged linearly along long chains of DNA base-pair sequences. In bacteria, each cell usually contains a single circular genophore, while eukaryotic organisms (such as plants and animals) have their DNA arranged in multiple linear chromosomes. These DNA strands are often extremely long; the largest human chromosome, for example, is about 247 million base pairs in length. The DNA of a chromosome is associated with structural proteins that organize, compact, and control access to the DNA, forming a material called chromatin; in eukaryotes, chromatin is usually composed of nucleosomes, segments of DNA wound around cores of histone proteins. The full set of hereditary material in an organism (usually the combined DNA sequences of all chromosomes) is called the genome.

DNA is most often found in the nucleus of cells, but Ruth Sager helped in the discovery of nonchromosomal genes found outside of the nucleus. In plants, these are often found in the chloroplasts and in other organisms, in the mitochondria. These nonchromosomal genes can still be passed on by either partner in sexual reproduction and they control a variety of hereditary characteristics that replicate and remain active throughout generations.

While haploid organisms have only one copy of each chromosome, most animals and many plants are diploid, containing two of each chromosome and thus two copies of every gene. The two alleles for a gene are located on identical loci of the two homologous chromosomes, each allele inherited from a different parent.

Many species have so-called sex chromosomes that determine the sex of each organism. In humans and many other animals, the Y chromosome contains the gene that triggers the development of the specifically male characteristics. In evolution, this chromosome has lost most of its content and also most of its genes, while the X chromosome is similar to the other chromosomes and contains many genes. This being said, Mary Frances Lyon discovered that there is X-chromosome inactivation during reproduction to avoid passing on twice as many genes to the offspring. Lyon's discovery led to the discovery of X-linked diseases.

Reproduction

When cells divide, their full genome is copied and each daughter cell inherits one copy. This process, called mitosis, is the simplest form of reproduction and is the basis for asexual reproduction. Asexual reproduction can also occur in multicellular organisms, producing offspring that inherit their genome from a single parent. Offspring that are genetically identical to their parents are called clones.

Eukaryotic organisms often use sexual reproduction to generate offspring that contain a mixture of genetic material inherited from two different parents. The process of sexual reproduction alternates between forms that contain single copies of the genome (haploid) and double copies (diploid). Haploid cells fuse and combine genetic material to create a diploid cell with paired chromosomes. Diploid organisms form haploids by dividing, without replicating their DNA, to create daughter cells that randomly inherit one of each pair of chromosomes. Most animals and many plants are diploid for most of their lifespan, with the haploid form reduced to single cell gametes such as sperm or eggs.

Although they do not use the haploid/diploid method of sexual reproduction, bacteria have many methods of acquiring new genetic information. Some bacteria can undergo conjugation, transferring a small circular piece of DNA to another bacterium. Bacteria can also take up raw DNA fragments found in the environment and integrate them into their genomes, a phenomenon known as transformation. These processes result in horizontal gene transfer, transmitting fragments of genetic information between organisms that would be otherwise unrelated. Natural bacterial transformation occurs in many bacterial species, and can be regarded as a sexual process for transferring DNA from one cell to another cell (usually of the same species). Transformation requires the action of numerous bacterial gene products, and its primary adaptive function appears to be repair of DNA damages in the recipient cell.

Recombination and genetic linkage

The diploid nature of chromosomes allows for genes on different chromosomes to assort independently or be separated from their homologous pair during sexual reproduction wherein haploid gametes are formed. In this way new combinations of genes can occur in the offspring of a mating pair. Genes on the same chromosome would theoretically never recombine. However, they do, via the cellular process of chromosomal crossover. During crossover, chromosomes exchange stretches of DNA, effectively shuffling the gene alleles between the chromosomes. This process of chromosomal crossover generally occurs during meiosis, a series of cell divisions that creates haploid cells. Meiotic recombination, particularly in microbial eukaryotes, appears to serve the adaptive function of repair of DNA damages.

The first cytological demonstration of crossing over was performed by Harriet Creighton and Barbara McClintock in 1931. Their research and experiments on corn provided cytological evidence for the genetic theory that linked genes on paired chromosomes do in fact exchange places from one homolog to the other.

The probability of chromosomal crossover occurring between two given points on the chromosome is related to the distance between the points. For an arbitrarily long distance, the probability of crossover is high enough that the inheritance of the genes is effectively uncorrelated. For genes that are closer together, however, the lower probability of crossover means that the genes demonstrate genetic linkage; alleles for the two genes tend to be inherited together. The amounts of linkage between a series of genes can be combined to form a linear linkage map that roughly describes the arrangement of the genes along the chromosome.

Genetic code

Genes express their functional effect through the production of proteins, which are molecules responsible for most functions in the cell. Proteins are made up of one or more polypeptide chains, each composed of a sequence of amino acids. The DNA sequence of a gene is used to produce a specific amino acid sequence. This process begins with the production of an RNA molecule with a sequence matching the gene's DNA sequence, a process called transcription.

This messenger RNA molecule then serves to produce a corresponding amino acid sequence through a process called translation. Each group of three nucleotides in the sequence, called a codon, corresponds either to one of the twenty possible amino acids in a protein or an instruction to end the amino acid sequence; this correspondence is called the genetic code. The flow of information is unidirectional: information is transferred from nucleotide sequences into the amino acid sequence of proteins, but it never transfers from protein back into the sequence of DNA—a phenomenon Francis Crick called the central dogma of molecular biology.

The specific sequence of amino acids results in a unique three-dimensional structure for that protein, and the three-dimensional structures of proteins are related to their functions. Some are simple structural molecules, like the fibers formed by the protein collagen. Proteins can bind to other proteins and simple molecules, sometimes acting as enzymes by facilitating chemical reactions within the bound molecules (without changing the structure of the protein itself). Protein structure is dynamic; the protein hemoglobin bends into slightly different forms as it facilitates the capture, transport, and release of oxygen molecules within mammalian blood.

A single nucleotide difference within DNA can cause a change in the amino acid sequence of a protein. Because protein structures are the result of their amino acid sequences, some changes can dramatically change the properties of a protein by destabilizing the structure or changing the surface of the protein in a way that changes its interaction with other proteins and molecules. For example, sickle-cell anemia is a human genetic disease that results from a single base difference within the coding region for the β-globin section of hemoglobin, causing a single amino acid change that changes hemoglobin's physical properties. Sickle-cell versions of hemoglobin stick to themselves, stacking to form fibers that distort the shape of red blood cells carrying the protein. These sickle-shaped cells no longer flow smoothly through blood vessels, having a tendency to clog or degrade, causing the medical problems associated with this disease.

Some DNA sequences are transcribed into RNA but are not translated into protein products—such RNA molecules are called non-coding RNA. In some cases, these products fold into structures which are involved in critical cell functions (e.g. ribosomal RNA and transfer RNA). RNA can also have regulatory effects through hybridization interactions with other RNA molecules (such as microRNA).

Nature and nurture

Although genes contain all the information an organism uses to function, the environment plays an important role in determining the ultimate phenotypes an organism displays. The phrase "nature and nurture" refers to this complementary relationship. The phenotype of an organism depends on the interaction of genes and the environment. An interesting example is the coat coloration of the Siamese cat. In this case, the body temperature of the cat plays the role of the environment. The cat's genes code for dark hair, thus the hair-producing cells in the cat make cellular proteins resulting in dark hair. But these dark hair-producing proteins are sensitive to temperature (i.e. have a mutation causing temperature-sensitivity) and denature in higher-temperature environments, failing to produce dark-hair pigment in areas where the cat has a higher body temperature. In a low-temperature environment, however, the protein's structure is stable and produces dark-hair pigment normally. The protein remains functional in areas of skin that are colder—such as its legs, ears, tail, and faceso the cat has dark hair at its extremities.

Environment plays a major role in effects of the human genetic disease phenylketonuria. The mutation that causes phenylketonuria disrupts the ability of the body to break down the amino acid phenylalanine, causing a toxic build-up of an intermediate molecule that, in turn, causes severe symptoms of progressive intellectual disability and seizures. However, if someone with the phenylketonuria mutation follows a strict diet that avoids this amino acid, they remain normal and healthy.

A common method for determining how genes and environment ("nature and nurture") contribute to a phenotype involves studying identical and fraternal twins, or other siblings of multiple births. Identical siblings are genetically the same since they come from the same zygote. Meanwhile, fraternal twins are as genetically different from one another as normal siblings. By comparing how often a certain disorder occurs in a pair of identical twins to how often it occurs in a pair of fraternal twins, scientists can determine whether that disorder is caused by genetic or postnatal environmental factors. One famous example involved the study of the Genain quadruplets, who were identical quadruplets all diagnosed with schizophrenia.

Gene regulation
The genome of a given organism contains thousands of genes, but not all these genes need to be active at any given moment. A gene is expressed when it is being transcribed into mRNA and there exist many cellular methods of controlling the expression of genes such that proteins are produced only when needed by the cell. Transcription factors are regulatory proteins that bind to DNA, either promoting or inhibiting the transcription of a gene. Within the genome of Escherichia coli bacteria, for example, there exists a series of genes necessary for the synthesis of the amino acid tryptophan. However, when tryptophan is already available to the cell, these genes for tryptophan synthesis are no longer needed. The presence of tryptophan directly affects the activity of the genes—tryptophan molecules bind to the tryptophan repressor (a transcription factor), changing the repressor's structure such that the repressor binds to the genes. The tryptophan repressor blocks the transcription and expression of the genes, thereby creating negative feedback regulation of the tryptophan synthesis process.

Differences in gene expression are especially clear within multicellular organisms, where cells all contain the same genome but have very different structures and behaviors due to the expression of different sets of genes. All the cells in a multicellular organism derive from a single cell, differentiating into variant cell types in response to external and intercellular signals and gradually establishing different patterns of gene expression to create different behaviors. As no single gene is responsible for the development of structures within multicellular organisms, these patterns arise from the complex interactions between many cells.

Within eukaryotes, there exist structural features of chromatin that influence the transcription of genes, often in the form of modifications to DNA and chromatin that are stably inherited by daughter cells. These features are called "epigenetic" because they exist "on top" of the DNA sequence and retain inheritance from one cell generation to the next. Because of epigenetic features, different cell types grown within the same medium can retain very different properties. Although epigenetic features are generally dynamic over the course of development, some, like the phenomenon of paramutation, have multigenerational inheritance and exist as rare exceptions to the general rule of DNA as the basis for inheritance.

Mutations

During the process of DNA replication, errors occasionally occur in the polymerization of the second strand. These errors, called mutations, can affect the phenotype of an organism, especially if they occur within the protein coding sequence of a gene. Error rates are usually very low—1 error in every 10–100 million bases—due to the "proofreading" ability of DNA polymerases. Processes that increase the rate of changes in DNA are called mutagenic: mutagenic chemicals promote errors in DNA replication, often by interfering with the structure of base-pairing, while UV radiation induces mutations by causing damage to the DNA structure. Chemical damage to DNA occurs naturally as well and cells use DNA repair mechanisms to repair mismatches and breaks. The repair does not, however, always restore the original sequence. A particularly important source of DNA damages appears to be reactive oxygen species produced by cellular aerobic respiration, and these can lead to mutations.

In organisms that use chromosomal crossover to exchange DNA and recombine genes, errors in alignment during meiosis can also cause mutations. Errors in crossover are especially likely when similar sequences cause partner chromosomes to adopt a mistaken alignment; this makes some regions in genomes more prone to mutating in this way. These errors create large structural changes in DNA sequence—duplications, inversions, deletions of entire regions—or the accidental exchange of whole parts of sequences between different chromosomes, chromosomal translocation.

Natural selection and evolution
Mutations alter an organism's genotype and occasionally this causes different phenotypes to appear. Most mutations have little effect on an organism's phenotype, health, or reproductive fitness. Mutations that do have an effect are usually detrimental, but occasionally some can be beneficial. Studies in the fly Drosophila melanogaster suggest that if a mutation changes a protein produced by a gene, about 70 percent of these mutations are harmful with the remainder being either neutral or weakly beneficial.

Population genetics studies the distribution of genetic differences within populations and how these distributions change over time. Changes in the frequency of an allele in a population are mainly influenced by natural selection, where a given allele provides a selective or reproductive advantage to the organism, as well as other factors such as mutation, genetic drift, genetic hitchhiking, artificial selection and migration.

Over many generations, the genomes of organisms can change significantly, resulting in evolution. In the process called adaptation, selection for beneficial mutations can cause a species to evolve into forms better able to survive in their environment. New species are formed through the process of speciation, often caused by geographical separations that prevent populations from exchanging genes with each other.

By comparing the homology between different species' genomes, it is possible to calculate the evolutionary distance between them and when they may have diverged. Genetic comparisons are generally considered a more accurate method of characterizing the relatedness between species than the comparison of phenotypic characteristics. The evolutionary distances between species can be used to form evolutionary trees; these trees represent the common descent and divergence of species over time, although they do not show the transfer of genetic material between unrelated species (known as horizontal gene transfer and most common in bacteria).

Model organisms

Although geneticists originally studied inheritance in a wide variety of organisms, the range of species studied has narrowed. One reason is that when significant research already exists for a given organism, new researchers are more likely to choose it for further study, and so eventually a few model organisms became the basis for most genetics research. Common research topics in model organism genetics include the study of gene regulation and the involvement of genes in development and cancer. Organisms were chosen, in part, for convenience—short generation times and easy genetic manipulation made some organisms popular genetics research tools. Widely used model organisms include the gut bacterium Escherichia coli, the plant Arabidopsis thaliana, baker's yeast (Saccharomyces cerevisiae), the nematode Caenorhabditis elegans, the common fruit fly (Drosophila melanogaster), the zebrafish (Danio rerio), and the common house mouse (Mus musculus).

Medicine

Medical genetics seeks to understand how genetic variation relates to human health and disease. When searching for an unknown gene that may be involved in a disease, researchers commonly use genetic linkage and genetic pedigree charts to find the location on the genome associated with the disease. At the population level, researchers take advantage of Mendelian randomization to look for locations in the genome that are associated with diseases, a method especially useful for multigenic traits not clearly defined by a single gene. Once a candidate gene is found, further research is often done on the corresponding (or homologous) genes of model organisms. In addition to studying genetic diseases, the increased availability of genotyping methods has led to the field of pharmacogenetics: the study of how genotype can affect drug responses.

Individuals differ in their inherited tendency to develop cancer, and cancer is a genetic disease. The process of cancer development in the body is a combination of events. Mutations occasionally occur within cells in the body as they divide. Although these mutations will not be inherited by any offspring, they can affect the behavior of cells, sometimes causing them to grow and divide more frequently. There are biological mechanisms that attempt to stop this process; signals are given to inappropriately dividing cells that should trigger cell death, but sometimes additional mutations occur that cause cells to ignore these messages. An internal process of natural selection occurs within the body and eventually mutations accumulate within cells to promote their own growth, creating a cancerous tumor that grows and invades various tissues of the body. Normally, a cell divides only in response to signals called growth factors and stops growing once in contact with surrounding cells and in response to growth-inhibitory signals. It usually then divides a limited number of times and dies, staying within the epithelium where it is unable to migrate to other organs. To become a cancer cell, a cell has to accumulate mutations in a number of genes (three to seven). A cancer cell can divide without growth factor and ignores inhibitory signals. Also, it is immortal and can grow indefinitely, even after it makes contact with neighboring cells. It may escape from the epithelium and ultimately from the primary tumor. Then, the escaped cell can cross the endothelium of a blood vessel and get transported by the bloodstream to colonize a new organ, forming deadly metastasis. Although there are some genetic predispositions in a small fraction of cancers, the major fraction is due to a set of new genetic mutations that originally appear and accumulate in one or a small number of cells that will divide to form the tumor and are not transmitted to the progeny (somatic mutations). The most frequent mutations are a loss of function of p53 protein, a tumor suppressor, or in the p53 pathway, and gain of function mutations in the Ras proteins, or in other oncogenes.

Research methods

DNA can be manipulated in the laboratory. Restriction enzymes are commonly used enzymes that cut DNA at specific sequences, producing predictable fragments of DNA. DNA fragments can be visualized through use of gel electrophoresis, which separates fragments according to their length.

The use of ligation enzymes allows DNA fragments to be connected. By binding ("ligating") fragments of DNA together from different sources, researchers can create recombinant DNA, the DNA often associated with genetically modified organisms. Recombinant DNA is commonly used in the context of plasmids: short circular DNA molecules with a few genes on them. In the process known as molecular cloning, researchers can amplify the DNA fragments by inserting plasmids into bacteria and then culturing them on plates of agar (to isolate clones of bacteria cells). "Cloning" can also refer to the various means of creating cloned ("clonal") organisms.

DNA can also be amplified using a procedure called the polymerase chain reaction (PCR). By using specific short sequences of DNA, PCR can isolate and exponentially amplify a targeted region of DNA. Because it can amplify from extremely small amounts of DNA, PCR is also often used to detect the presence of specific DNA sequences.

DNA sequencing and genomics
DNA sequencing, one of the most fundamental technologies developed to study genetics, allows researchers to determine the sequence of nucleotides in DNA fragments. The technique of chain-termination sequencing, developed in 1977 by a team led by Frederick Sanger, is still routinely used to sequence DNA fragments. Using this technology, researchers have been able to study the molecular sequences associated with many human diseases.

As sequencing has become less expensive, researchers have sequenced the genomes of many organisms using a process called genome assembly, which uses computational tools to stitch together sequences from many different fragments. These technologies were used to sequence the human genome in the Human Genome Project completed in 2003. New high-throughput sequencing technologies are dramatically lowering the cost of DNA sequencing, with many researchers hoping to bring the cost of resequencing a human genome down to a thousand dollars.

Next-generation sequencing (or high-throughput sequencing) came about due to the ever-increasing demand for low-cost sequencing. These sequencing technologies allow the production of potentially millions of sequences concurrently. The large amount of sequence data available has created the subfield of genomics, research that uses computational tools to search for and analyze patterns in the full genomes of organisms. Genomics can also be considered a subfield of bioinformatics, which uses computational approaches to analyze large sets of biological data. A common problem to these fields of research is how to manage and share data that deals with human subject and personally identifiable information.

Society and culture
On 19 March 2015, a group of leading biologists urged a worldwide ban on clinical use of methods, particularly the use of CRISPR and zinc finger, to edit the human genome in a way that can be inherited. In April 2015, Chinese researchers reported results of basic research to edit the DNA of non-viable human embryos using CRISPR.

title: Genetics


text:
George Pappas

George Sotiros Pappas (born 1942) is a professor of philosophy at Ohio State University. Pappas specializes in epistemology, the history of early modern philosophy, philosophy of religion and metaphysics. He is of Greek and English origin.

He is the author of the Stanford Encyclopedia of Philosophy entry on "Internalist versus Externalist" conceptions of epistemic justification.

He was co-editor (with Marshall Swain) of Essays on Knowledge and Justification (1978), an anthology of essays relating to the Gettier problem used as a core text in undergraduate epistemology courses.

Pappas is an editorial consultant of Berkeley Studies.

Studies in Berkeley's philosophy
Pappas is known to be a leading Berkeley scholar; his essay "Berkeley and Scepticism" was in 1993 awarded the International Berkeley Prize. Pappas is a regular participant of International Berkeley Conferences. At one such conference, celebrating the 300th anniversary of George Berkeley's birth, Pappas propounded a new approach to the relationship between Berkeley's anti-abstractionism and "esse est percipi" principle. On Pappas' reading, Berkeley's two theses — that there are no abstract ideas and that sensible objects must be perceived in order to exist — entail one another.

"Pappas' formulation of the relationship between these two propositions is ingenious and merits his verdict that it is a 'very exciting result' ... So far as I know, his thesis is original. Some writers, to be sure, have some close to suggesting that the first proposition is a necessary condition for the truth of the second, but I cannot think of a commentator who holds that it is both a necessary and sufficient condition."

Pappas' interpretation of Berkeley's esse is percipi thesis has sparked much discussion. In 1989, the Garland Publishing Company brought out a 15-volume collection of major works on Berkeley; Pappas' paper "Abstract ideas and the 'esse is percipi' thesis" was included in the third volume, as it was considered to be a significant contribution to Berkeley scholarship.

Pappas developed his treatment of Berkeley's "esse est percipi" principle to repudiate the "inherence interpretation of Berkeley", upon which Edwin E. Allaire, among others, elaborated.

"That account is put forward to answer an extremely perplexing question in the history of philosophy: Why did Berkeley embrace idealism, i. e., why did he hold that esse est percipi, that to be is to be perceived?"

After emerging in the early 1960s, the "inherence account" attracted numerous proponents and became an influential element of contemporary Berkeley scholarship. In his paper "Ideas, minds, and Berkeley" Pappas revealed some discrepancies between fountain-head evidences and Allaire's approach to a reconstruction of Berkeley's idealism. Pappas' critical examination of the "inherence account" is greatly appreciated by Berkeley scholars. Pappas' penetrating remarks compelled Edwin B. Allaire to revise and improve his conception. Even those who share Allaire's account of Berkeley's idealism acknowledge Pappas' article to be "an excellent review and critique of the IA [inherence account]."

In 2000, Pappas published his monograph Berkeley's thought in which some parts were based on earlier papers of his. While writings by A. A. Luce or Geoffrey Warnock are long outdated, Berkeley's thought is often included in lists of recommended literature on Berkeley's philosophy.

title: George Pappas