Voynich manuscript

Voynich Manuscript
Beinecke Rare Book and Manuscript Library, Yale University MS 408
One of the foldout pages in the Voynich manuscript
Type	Manuscript codex
Date	Early 15th century
Place of origin	Possibly northern Italy
Material	Vellum
Size	23.5 by 16.2 by 5 centimetres (9.3 by 6.4 by 2.0 in); about 240 pages

The Voynich manuscript, described as "the world's most mysterious manuscript", is a work which dates to the early 15th century (1404–1438), possibly from northern Italy. It is named after the book dealer Wilfrid Voynich, who purchased it in 1912.

Some pages are missing, but the current version comprises about 240 vellum pages, most with illustrations. Much of the manuscript resembles herbal manuscripts of the 1500s, seeming to present illustrations and information about plants and their possible uses for medical purposes. However, most of the plants do not match known species, and the manuscript's script and language remain unknown and unreadable. Possibly some form of encrypted ciphertext, the Voynich manuscript has been studied by many professional and amateur cryptographers, including American and British codebreakers from both World War I and World War II. As yet, it has defied all decipherment attempts, becoming a famous case of historical cryptology. The mystery surrounding it has excited the popular imagination, making the manuscript a subject of both fanciful theories and novels. None of the many speculative solutions proposed over the last hundred years has yet been independently verified.

The Voynich manuscript was donated to Yale University's Beinecke Rare Book and Manuscript Library in 1969, where it is catalogued under call number MS 408 and called a "Cipher Manuscript".

Content

The manuscript measures 23.5 by 16.2 by 5 centimetres (9.3 by 6.4 by 2.0 in), with hundreds of vellum pages collected into eighteen quires. It is made up of, depending on how some of its unusual fold-out multi-part pages are counted, approximately 240 pages in total. The top righthand corner of each recto (righthand) page has been numbered from 1 to 116, probably by one of the manuscript's later owners. From the various numbering gaps, it seems likely that in the past the manuscript had at least 272 pages, some of which were already missing when Wilfrid Voynich acquired the manuscript in 1912. There is strong evidence that many of the book's bifolios were reordered at various points in its history, and that the original page order may well have been quite different from what we see today.

Based on modern analysis, it has been determined that a quill pen and iron gall ink were used for the text and figure outlines. Colored paint was applied (somewhat crudely) to the figures, possibly at a later date.

Text

The text was clearly written from left to right, with a slightly ragged right margin. Longer sections are broken into paragraphs, sometimes with star- or flower-like " bullets" in the left margin. There is no obvious punctuation, and no indications of any errors or corrections made at any place in the document. The ductus flows smoothly, giving the impression that the symbols were not enciphered, as there is no delay between characters as would normally be expected in written encoded text. Whoever the scribe was, he or she was practiced in writing the script. However, such writing fluency could also be achieved by copying prepared coded text from some other source, such as a wax tablet or separate manuscript.

The text consists of over 170,000 glyphs, usually separated from each other by narrow gaps. Most of the glyphs are written with one or two simple pen strokes. While there is some dispute as to whether certain glyphs are distinct or not, an alphabet with 20–30 glyphs would account for virtually all of the text; the exceptions are a few dozen rarer characters that occur only once or twice each. Various transcription alphabets have been created, to equate the Voynich glyphs with Latin characters in order to help with cryptanalysis, such as the European Voynich Alphabet. The first major one was created by cryptographer William F. Friedman in the 1940s, where each line of the manuscript was transcribed to an IBM punch card to make it machine-readable.

Wider gaps divide the text into about 35,000 "words" of varying length. These seem to follow phonological or orthographic laws of some sort, e.g., certain characters must appear in each word (like English vowels), some characters never follow others, some may be doubled or tripled but others may not, etc.

Statistical analysis of the text reveals patterns similar to those of natural languages. For instance, the word entropy (about 10 bits per word) is similar to that of English or Latin texts. Some words occur only in certain sections, or in only a few pages; others occur throughout the manuscript. There are very few repetitions among the thousand or so "labels" attached to the illustrations. In the herbal section, the first word on each page occurs only on that page and may possibly be the name of the plant.

On the other hand, the Voynich manuscript's "language" is quite unlike European languages in several aspects. There are practically no words comprising more than ten glyphs, yet there are also few one- or two-letter words. The distribution of letters within words is also rather peculiar: some characters occur only at the beginning of a word, some only at the end, and some always in the middle section. While Semitic alphabets have many letters that are written differently depending on whether they occur at the beginning, in the middle or at the end of a word, letters of the Latin, Cyrillic, and Greek alphabets are generally written the same way regardless of their position within a word (with the Greek letter sigma and the obsolete long s being notable exceptions).

The text seems to be more repetitive than typical European languages; there are instances where the same common word appears up to three times in a row. Words that differ by only one letter also repeat with unusual frequency, causing single-substitution alphabet decipherings to yield babble-like text. Elizebeth Friedman in 1962 described such attempts as "doomed to utter frustration".

There are only a few words in the manuscript written in a seemingly Latin script. On the last page, there are four lines of writing written in rather distorted Latin letters, except for two words in the main script. The lettering resembles European alphabets of the late 14th and 15th centuries, but the words do not seem to make sense in any language. Also, a series of diagrams in the "astronomical" section has the names of ten of the months (from March to December) written in Latin script, with spelling suggestive of the medieval languages of France, northwest Italy or the Iberian Peninsula. However, it is not known whether these bits of Latin script were part of the original text or were added later.

Illustrations

The illustrations of the manuscript shed little light on the precise nature of its text but imply that the book consists of six "sections", with different styles and subject matter. Except for the last section, which contains only text, almost every page contains at least one illustration. Following are the sections and their conventional names:

Herbal

Each page displays one plant (sometimes two) and a few paragraphs of text—a format typical of European herbals of the time. Some parts of these drawings are larger and cleaner copies of sketches seen in the "pharmaceutical" section. None of the plants depicted are unambiguously identifiable.

Astronomical

Contains circular diagrams, some of them with suns, moons, and stars, suggestive of astronomy or astrology. One series of 12 diagrams depicts conventional symbols for the zodiacal constellations (two fish for Pisces, a bull for Taurus, a hunter with crossbow for Sagittarius, etc.). Each of these has 30 female figures arranged in two or more concentric bands. Most of the females are at least partly naked, and each holds what appears to be a labeled star or is shown with the star attached by what could be a tether or cord of some kind to either arm. The last two pages of this section ( Aquarius and Capricornus, roughly January and February) were lost, while Aries and Taurus are split into four paired diagrams with 15 women and 15 stars each. Some of these diagrams are on fold-out pages.

Biological

A dense continuous text interspersed with figures, mostly showing small naked women, some wearing crowns, bathing in pools or tubs connected by an elaborate network of pipes, some of them strongly reminiscent of body organs.

Cosmological

More circular diagrams, but of an obscure nature. This section also has foldouts; one of them spans six pages and contains a map or diagram, with nine "islands" or "rosettes" connected by " causeways" and containing castles, as well as what may possibly be a volcano.

Pharmaceutical

Many labeled drawings of isolated plant parts (roots, leaves, etc.); objects resembling apothecary jars, ranging in style from the mundane to the fantastical; and a few text paragraphs.

Recipes

Many short paragraphs, each marked with a flower- or star-like "bullet".

Purpose

The overall impression given by the surviving leaves of the manuscript is that it was meant to serve as a pharmacopoeia or to address topics in medieval or early modern medicine. However, the puzzling details of illustrations have fueled many theories about the book's origins, the contents of its text, and the purpose for which it was intended.

The first section of the book is almost certainly herbal, but attempts to identify the plants, either with actual specimens or with the stylized drawings of contemporary herbals, have largely failed. Few of the plant drawings (such as a wild pansy and the maidenhair fern) can be identified with reasonable certainty. Those herbal pictures that match pharmacological sketches appear to be clean copies of these, except that missing parts were completed with improbable-looking details. In fact, many of the plant drawings in the herbal section seem to be composite: the roots of one species have been fastened to the leaves of another, with flowers from a third.

Brumbaugh believed that one illustration depicted a New World sunflower, which would help date the manuscript and open up intriguing possibilities for its origin. However, the resemblance is slight, especially when compared to the original wild species; and, since the scale of the drawing is not known, the plant could be many other members of the same family, which includes the common daisy, chamomile, and many other species from all over the world.

The basins and tubes in the "biological" section are sometimes interpreted as implying a connection to alchemy, yet bear little obvious resemblance to the alchemical equipment of the period.

Astrological considerations frequently played a prominent role in herb gathering, bloodletting and other medical procedures common during the likeliest dates of the manuscript. However, apart from the obvious Zodiac symbols, and one diagram possibly showing the classical planets, no one has been able to interpret the illustrations within known astrological traditions (European or otherwise).

A circular drawing in the "astronomical" section depicts an irregularly shaped object with four curved arms, which, in 1928, antiquarian William Romaine Newbold interpreted as a picture of a galaxy, which could only be obtained with a telescope. Similarly, he interpreted other drawings as cells seen through a microscope. However, Newbold's analysis has since been dismissed as overly speculative.

History

Much of the early history of the book is unknown, though the text and illustrations are all characteristically European. It was brought to modern attention in 1912 when it was purchased at the Villa Mondragone, near Rome, by antique book dealer Wilfrid Voynich. When Voynich first discovered the manuscript, his first impression was that it dated from the 13th century.

In 2009, University of Arizona researchers performed C14 dating on the manuscript's vellum, which they assert (with 95% confidence) was made between 1404 and 1438. In addition, the McCrone Research Institute in Chicago found that the paints in the manuscript were of materials to be expected from that period of European history. It has also been suggested that the McCrone Research Institute found that much of the ink was added not long after the creation of the parchment, but the official report contains no statement to this effect.

Based on a 1666 letter that accompanied the manuscript when it was being sent from Johannes Marcus to Athanasius Kircher, the book once belonged to Emperor Rudolf II (1552–1612), who paid 600 gold ducats (approximately USD $80,000 in 2011) for it. The book was then given or lent to Jacobus Horcicky de Tepenecz (died 1622), the head of Rudolf's botanical gardens. With modern ultraviolet lighting methods, Tepenecz's name can be seen faintly on the first page of the manuscript, and the handwriting is consistent with Tepenecz's name in other books that he owned.

The next confirmed owner is Georg Baresch, an obscure alchemist in Prague. Baresch apparently was just as puzzled as modern scientists about this " Sphynx" that had been "taking up space uselessly in his library" for many years. On learning that Athanasius Kircher, a Jesuit scholar from the Collegio Romano, had published a Coptic ( Egyptian) dictionary and "deciphered" the Egyptian hieroglyphs, Baresch sent a sample copy of the script to Kircher in Rome (twice), asking for clues. His 1639 letter to Kircher is the earliest confirmed mention of the manuscript that has been found so far.

It is not known whether Kircher answered the request, but apparently, he was interested enough to try to acquire the book, which Baresch refused to yield. Upon Baresch's death, the manuscript passed to his friend Jan Marek Marci (1595–1667) (Johannes Marcus Marci), then rector of Charles University in Prague, who a few years later sent the book to Kircher, his longtime friend and correspondent. Marci's 1666 cover letter (written in Latin) was still with the manuscript when Voynich purchased it:

Reverend and Distinguished Sir, Father in Christ: This book, bequeathed to me by an intimate friend, I destined for you, my very dear Athanasius, as soon as it came into my possession, for I was convinced that it could be read by no one except yourself. The former owner of this book asked your opinion by letter, copying and sending you a portion of the book from which he believed you would be able to read the remainder, but he at that time refused to send the book itself. To its deciphering he devoted unflagging toil, as is apparent from attempts of his which I send you herewith, and he relinquished hope only with his life. But his toil was in vain, for such Sphinxes as these obey no one but their master, Kircher. Accept now this token, such as it is and long overdue though it be, of my affection for you, and burst through its bars, if there are any, with your wonted success. Dr. Raphael, a tutor in the Bohemian language to Ferdinand III, then King of Bohemia, told me the said book belonged to the Emperor Rudolph and that he presented to the bearer who brought him the book 600 ducats. He believed the author was Roger Bacon, the Englishman. On this point I suspend judgement; it is your place to define for us what view we should take thereon, to whose favour and kindness I unreservedly commit myself and remain,

— At the command of your Reverence,
Joannes Marcus Marci of Cronland
Prague, 19th August, 1666

There are no records of the book for the next 200 years, but in all likelihood it was stored with the rest of Kircher's correspondence in the library of the Collegio Romano (now the Pontifical Gregorian University). It probably remained there until the troops of Victor Emmanuel II of Italy captured the city in 1870 and annexed the Papal States. The new Italian government decided to confiscate many properties of the Church, including the library of the Collegio. According to investigations by Xavier Ceccaldi and others, just before this happened, many books of the University's library were hastily transferred to the personal libraries of its faculty, which were exempt from confiscation. Kircher's correspondence was among those books—and so apparently was the Voynich manuscript, as it still bears the ex libris of Petrus Beckx, head of the Jesuit order and the University's Rector at the time.

Beckx's "private" library was moved to the Villa Mondragone, Frascati, a large country palace near Rome that had been bought by the Society of Jesus in 1866 and housed the headquarters of the Jesuits' Ghislieri College.

Around 1912, the Collegio Romano was short of money and decided to discreetly sell some of its holdings. Wilfrid Voynich acquired 30 manuscripts, among them the manuscript that now bears his name. In 1930, after his death, the manuscript was inherited by his widow, Ethel Lilian Voynich (known as the author of the novel The Gadfly and daughter of famous mathematician George Boole). She died in 1960 and left the manuscript to her close friend, Miss Anne Nill. In 1961, Nill sold the book to another antique book dealer, Hans P. Kraus. Unable to find a buyer, Kraus donated the manuscript to Yale University in 1969, where it was catalogued as "MS 408". In discussions, it is sometimes also referred to as "Beinecke MS 408".

Authorship hypotheses

Many people have been proposed as possible authors of the Voynich manuscript.

Marci's 1666 cover letter to Kircher says that, according to his friend, the late Raphael Mnishovsky, the book had once been bought by Rudolf II, Holy Roman Emperor and King of Bohemia (1552–1612), for 600 ducats (66.42 troy ounce actual gold weight, around US$80,831.20 as of 2011). (Mnishovsky had died 22 years earlier, in 1644, and the deal must have occurred before Rudolf's abdication in 1611—at least 55 years before Marci's letter.) According to the letter, Mnishovsky (but not necessarily Rudolf) speculated that the author was the Franciscan friar and polymath Roger Bacon (1214–94). Even though Marci said that he was "suspending his judgment" about this claim, it was taken quite seriously by Wilfrid Voynich, who did his best to confirm it. His conviction strongly influenced most deciphering attempts for the next 80 years.

The assumption that Roger Bacon was the author led Voynich to conclude that the person who sold the manuscript to Rudolf could only have been John Dee (1527–1608), a mathematician and astrologer at the court of Queen Elizabeth I, known to have owned a large collection of Bacon's manuscripts. This theory is also conveyed by Voynich manuscript scholar Gordon Rugg. Dee and his scrier ( mediumic assistant) Edward Kelley lived in Bohemia for several years, where they had hoped to sell their services to the emperor. However, this seems quite unlikely, because Dee's meticulously kept diaries do not mention that sale. If the Voynich manuscript author is not Bacon, a supposed connection to Dee is much weakened. It is possible that Dee himself may have written it and spread the rumor that it was originally a work of Bacon's in the hopes of later selling it.

Dee's companion in Prague, Edward Kelley, was a self-styled alchemist who claimed to be able to turn copper into gold by means of a secret powder that he had dug out of a Bishop's tomb in Wales. As Dee's scrier, he claimed to be able to invoke angels through a shewstone and had long conversations with them, which Dee dutifully noted down. The angels' language was called Enochian, after Enoch, the Biblical father of Methuselah; according to legend, he had been taken on a tour of heaven by angels and had later written a book about what he saw there. Several people have suggested that Kelley could have fabricated the Voynich manuscript to swindle the emperor (who was already paying Kelley for his supposed alchemical expertise).

Fabrication by Voynich

Some suspected Voynich of having fabricated the manuscript himself. As an antique book dealer, he probably had the necessary knowledge and means, and a "lost book" by Roger Bacon would have been worth a fortune. Furthermore, Baresch's letter (and Marci's as well) only establish the existence of a manuscript, not that the Voynich manuscript is the same one spoken of there. In other words, these letters could possibly have been the motivation for Voynich to fabricate the manuscript (assuming he was aware of them), rather than as proofs authenticating it. However, many consider the expert internal dating of the manuscript and the recent discovery of Baresch's letter to Kircher as having eliminated this possibility.

Other theories

A photostatic reproduction of the first page of the Voynich manuscript, taken by Voynich sometime before 1921, showed some faint writing that had been erased. With the help of chemicals, the text could be read as the name "Jacobj à Tepenece". This is taken to be Jakub Hořčický of Tepenec, who was also known by his Latin name: Jacobus Sinapius (1575–1622). He was a specialist in herbal medicine, Rudolph II's personal physician, and curator of his botanical gardens. Voynich, and many other people after him, concluded from this "signature" that Jacobus owned the Voynich manuscript before Baresch and saw in that a confirmation of Mnishovsky's story. Others have suggested that Jacobus himself could be the author.

However, that writing does not match Jacobus's signature, as found in a document located by Jan Hurych in 2003. It is possible that the writing on page f1r was added by a later owner or librarian and is only this person's guess as to the book's author. (In the Jesuit history books that were available to Kircher, Jesuit-educated Jacobus is the only alchemist or doctor from Rudolf's court who deserves a full-page entry, while, for example, Tycho Brahe is barely mentioned.) Moreover, the chemicals applied by Voynich have so degraded the vellum that hardly a trace of the signature can be seen today; thus, there is also the suspicion that the signature was fabricated by Voynich in order to strengthen the Roger Bacon theory.

Jan Marek Marci met Kircher when he led a delegation from Charles University to Rome in 1638, and over the next 27 years, the two scholars exchanged many letters on a variety of scientific subjects. Marci's trip was part of a continuing struggle by the secularist side of the university to maintain their independence from the Jesuits, who ran the rival Clementinum college in Prague. In spite of those efforts, the two universities were merged in 1654, under Jesuit control. It has therefore been speculated that political animosity against the Jesuits led Marci to fabricate Baresch's letters, and later the Voynich manuscript, in an attempt to expose and discredit their "star" Kircher.

Marci's personality and knowledge appear to have been adequate for this task; and Kircher was an easy target. Indeed, Baresch's letter bears some resemblance to a hoax that orientalist Andreas Mueller once played on Kircher. Mueller concocted an unintelligible manuscript and sent it to Kircher with a note explaining that it had come from Egypt. He asked Kircher for a translation, and Kircher, reportedly, produced one at once. The only proofs of Georg Baresch's existence are three letters sent to Kircher: one by Baresch (1639), and two by Marci (about a year later). It is also curious that the correspondence between Marci and Kircher ends in 1666, precisely with the Voynich manuscript "cover letter".

However, Marci's secret grudge against the Jesuits is pure conjecture: a faithful Catholic, he himself had studied to become a Jesuit, and, shortly before his death in 1667, he was granted honorary membership in their Order.

Raphael Mnishovsky, the friend of Marci who was the reputed source of Bacon's story, was himself a cryptographer (among many other things) and apparently invented a cipher that he claimed was uncrackable (ca. 1618). This has led to the theory that he produced the Voynich manuscript as a practical demonstration of his cipher and made poor Baresch his unwitting test subject. After Kircher published his book on Coptic, Mnishovsky (so the theory goes) may have thought that stumping him would be a much better trophy than stumping Baresch and convinced the alchemist to ask the Jesuit's help. He would have invented the Roger Bacon story to motivate Baresch. Indeed, the disclaimer in the Voynich manuscript cover letter could mean that Marci suspected a lie. However, there is no definite evidence for this theory.

Leonell C. Strong, a cancer research scientist and amateur cryptographer, believed that the solution to the Voynich manuscript was a "peculiar double system of arithmetical progressions of a multiple alphabet". Strong claimed that the plaintext revealed the Voynich manuscript to be written by the 16th-century English author Anthony Ascham, whose works include A Little Herbal, published in 1550. Although the Voynich manuscript does contain sections resembling A Little Herbal, the main argument against this theory is that it is unknown where Ascham would have obtained such literary and cryptographic knowledge.

In his 2006 book, Nick Pelling proposed that the Voynich manuscript was written by Antonio Averlino (also known as "Filarete"), an Italian Renaissance architect. From a 1465 letter by Francesco Filelfo, it is known that Averlino intended travelling to Constantinople: yet not long before in September 1461, the Venetian border guards in Crete had sent Matteo di Andrea de' Pasti back to Venice in chains for carrying a copy of Roberto Valturio's De Re Militari on a similar journey East on behalf of Sigismondo Pandolfo Malatesta. To avoid this outcome on his own journey to the Ottoman Empire, Averlino - according to Pelling's hypothesis - constructed the Voynich manuscript to carry his own books of engineering and military secrets. Echoing John Tiltman's analysis, Pelling conjectures that the manuscript was enciphered using a broad set of simple cryptographic and steganographic components appropriate to the mid-15th century: and that these were consciously arranged in a complicated system so as to produce ciphertext resembling a medieval document in an unknown language, complete with apparent consonant-vowel pairing of letters and fake page references. He also concludes that most of the marginalia were added by the original author, but that when later owners tried to physically restore the badly faded text, their incorrect guesses at what these had originally read caused them to become unreadable.

Hoax

The bizarre features of the Voynich manuscript text (such as the doubled and tripled words), the suspicious contents of its illustrations (such as the chimeric plants) and its lack of historical reference support the idea that the manuscript is a hoax. In other words, if no one is able to extract meaning from the book, perhaps this is because the document contains no meaningful content in the first place.

Between 1976 and 1978, Italian artist Luigi Serafini proved that, with enough determination, such a text can be created. His Codex Seraphinianus also contains pictures of imaginary plants, and a language that has been studied by linguists for decades.

The argument for authenticity, on the other hand, is that the manuscript appears too sophisticated to be a hoax. While hoaxes of the period tended to be quite crude, the Voynich manuscript exhibits many subtle characteristics which show up only after careful statistical analysis. These fine touches require much more work than would have been necessary for a simple forgery, and some of the complexities are only visible with modern tools. The question then arises: why would the author employ such a complex and laborious forging algorithm in the creation of a simplistic hoax, if no one in the expected audience (that is, the creator's contemporaries) could tell the difference?

Various hoax theories have been proposed over time:

In 2003, computer scientist Gordon Rugg showed that text with characteristics similar to the Voynich manuscript could have been produced using a table of word prefixes, stems, and suffixes, which would have been selected and combined by means of a perforated paper overlay. The latter device, known as a Cardan grille, was invented around 1550 as an encryption tool, more than 100 years after the estimated creation date of the Voynich manuscript. Some maintain that the similarity between the pseudo-texts generated in Gordon Rugg's experiments and the Voynich manuscript is superficial, and the grille method could be used to emulate any language to a certain degree.

In April 2007, a study by Austrian researcher Andreas Schinner published in Cryptologia supported the hoax hypothesis. Schinner showed that the statistical properties of the manuscript's text were more consistent with meaningless gibberish produced using a quasi- stochastic method such as the one described by Rugg, than with Latin and medieval German texts.

Language hypotheses

There are many theories about the Voynich manuscript's "language":

Constructed language

The peculiar internal structure of Voynich manuscript "words" led William F. Friedman to conjecture that the text could be a constructed language. In 1950, Friedman asked the British army officer John Tiltman to analyze a few pages of the text, but Tiltman did not share this conclusion. In a paper in 1967, Brigadier Tiltman said, "After reading my report, Mr. Friedman disclosed to me his belief that the basis of the script was a very primitive form of synthetic universal language such as was developed in the form of a philosophical classification of ideas by Bishop Wilkins in 1667 and Dalgarno a little later. It was clear that the productions of these two men were much too systematic, and anything of the kind would have been almost instantly recognisable. My analysis seemed to me to reveal a cumbersome mixture of different kinds of substitution".

The concept of an artificial language is quite old, as attested by John Wilkins's Philosophical Language (1668), but still postdates the generally accepted origin of the Voynich manuscript by two centuries. In most known examples, categories are subdivided by adding suffixes; as a consequence, a text in a particular subject would have many words with similar prefixes—for example, all plant names would begin with similar letters, and likewise for all diseases, etc. This feature could then explain the repetitious nature of the Voynich text. However, no one has been able yet to assign a plausible meaning to any prefix or suffix in the Voynich manuscript.

Ciphers

According to the "letter-based cipher" theory, the Voynich manuscript contains a meaningful text in some European language, that was intentionally rendered obscure by mapping it to the Voynich manuscript "alphabet" through a cipher of some sort—an algorithm that operated on individual letters. This has been the working hypothesis for most twentieth-century deciphering attempts, including an informal team of NSA cryptographers led by William F. Friedman in the early 1950s.

The main argument for this theory is that the use of a strange alphabet by a European author is awkward to explain except as an attempt to hide information. Indeed, even Roger Bacon knew about ciphers, and the estimated date for the manuscript roughly coincides with the birth of cryptography in Europe as a relatively systematic discipline.

The counterargument is that almost all cipher systems consistent with that era fail to match what we see in the Voynich manuscript. For example, simple monoalphabetic ciphers can be excluded because the distribution of letter frequencies does not resemble that of any common language; while the small number of different letter-shapes used implies that we can rule out nomenclator ciphers and homophonic ciphers, because these typically employ larger cipher alphabets. Similarly, polyalphabetic ciphers, first invented by Alberti in the 1460s and including the later Vigenère cipher, usually yield ciphertexts where all cipher shapes occur with roughly equal probability, quite unlike the language-like letter distribution the Voynich Manuscript appears to have.

However, the presence of many tightly grouped shapes in the Voynich manuscript (such as 'or', 'ar', 'ol', 'al', 'an', 'ain', 'aiin', 'air', 'aiir', 'am', 'ee', 'eee', etc.) does suggest that its cipher system may make use of a verbose cipher, where single letters in a plaintext get enciphered into groups of fake letters. For example, the first two lines of page f15v (the image on the right here) contain 'or or or' and 'or or oro r', which strongly resemble how Roman numbers such as 'CCC' or 'XXXX' would look if verbosely enciphered. Yet even though verbose encipherment is arguably the best match, it still falls well short of being able to explain all of the Voynich manuscript's odd textual properties.

It is also entirely possible that the encryption system started from a fundamentally simple cipher and then augmented it by adding nulls (meaningless symbols), homophones (duplicate symbols), transposition cipher (letter rearrangement), false word breaks and so on.

Codes

According to the "codebook cipher" theory, the Voynich manuscript "words" would actually be codes to be looked up in a "dictionary" or codebook. The main evidence for this theory is that the internal structure and length distribution of many words are similar to those of Roman numerals—which, at the time, would be a natural choice for the codes. However, book-based ciphers are viable only for short messages, because they are very cumbersome to write and to read.

Micrography

Following its 1912 rediscovery, one of the earliest efforts to unlock the book's secrets (and the first of many premature claims of decipherment) was made in 1921 by William Newbold of the University of Pennsylvania. His singular hypothesis held that the visible text is meaningless itself, but that each apparent "letter" is in fact constructed of a series of tiny markings only discernible under magnification. These markings were supposed to be based on ancient Greek shorthand, forming a second level of script that held the real content of the writing. Newbold claimed to have used this knowledge to work out entire paragraphs proving the authorship of Bacon and recording his use of a compound microscope four hundred years before van Leeuwenhoek. However, John Matthews Manly of the University of Chicago pointed out serious flaws in this theory. Each shorthand character was assumed to have multiple interpretations, with no reliable way to determine which was intended for any given case. Newbold's method also required rearranging letters at will until intelligible Latin was produced. These factors alone ensure the system enough flexibility that nearly anything at all could be discerned from the microscopic markings. Although evidence of micrography using the Hebrew language can be traced as far back as the ninth century, it is nowhere near as compact or complex as the shapes Newbold made out. Close study of the manuscript revealed the markings to be artifacts caused by the way ink cracks as it dries on rough vellum. Perceiving significance in these artifacts can be attributed to pareidolia. Thanks to Manly's thorough refutation, the micrography theory is now generally disregarded.

Steganography

This theory holds that the text of the Voynich manuscript is mostly meaningless, but contains meaningful information hidden in inconspicuous details—e.g. the second letter of every word, or the number of letters in each line. This technique, called steganography, is very old, and was described by Johannes Trithemius in 1499. Though it has been suggested that the plain text was to be extracted by a Cardan grille of some sort, this seems somewhat unlikely because the words and letters are not arranged on anything like a regular grid. Still, steganographic claims are hard to prove or disprove, since stegotexts can be arbitrarily hard to find. An argument against steganography is that having a cipher-like cover text highlights the very existence of the secret message, which would be self-defeating: yet because the cover text no less resembles an unknown natural language, this argument is not hugely persuasive.

It has been suggested that the meaningful text could be encoded in the length or shape of certain pen strokes. There are indeed examples of steganography from about that time that use letter shape ( italic vs. upright) to hide information. However, when examined at high magnification, the Voynich manuscript pen strokes seem quite natural, and substantially affected by the uneven surface of the vellum.

Exotic natural language

The linguist Jacques Guy once suggested that the Voynich manuscript text could be some exotic natural language, written in the plain with an invented alphabet. The word structure is similar to that of many language families of East and Central Asia, mainly Sino-Tibetan (Chinese, Tibetan, and Burmese), Austroasiatic ( Vietnamese, Khmer, etc.) and possibly Tai ( Thai, Lao, etc.). In many of these languages, the " words" have only one syllable; and syllables have a rather rich structure, including tonal patterns.

This theory has some historical plausibility. While those languages generally had native scripts, these were notoriously difficult for Western visitors. This difficulty motivated the invention of several phonetic scripts, mostly with Latin letters but sometimes with invented alphabets. Although the known examples are much later than the Voynich manuscript, history records hundreds of explorers and missionaries who could have done it—even before Marco Polo's thirteenth century journey, but especially after Vasco da Gama sailed the sea route to the Orient in 1499. The Voynich manuscript author could also be a native of East Asia who lived in Europe, or who was educated at a European mission.

The main argument for this theory is that it is consistent with all statistical properties of the Voynich manuscript text which have been tested so far, including doubled and tripled words (which have been found to occur in Chinese and Vietnamese texts at roughly the same frequency as in the Voynich manuscript). It also explains the apparent lack of numerals and Western syntactic features (such as articles and copulas), and the general inscrutability of the illustrations. Another possible hint is two large red symbols on the first page, which have been compared to a Chinese-style book title, inverted and badly copied. Also, the apparent division of the year into 360 degrees (rather than 365 days), in groups of 15 and starting with Pisces, are features of the Chinese agricultural calendar (jie qi, 節氣). The main argument against the theory is the fact that no one (including scholars at the Chinese Academy of Sciences in Beijing) has been able to find any clear examples of Asian symbolism or Asian science in the illustrations.

In 1976, James Child of the National Security Agency proposed that the manuscript was written in a "hitherto unknown North Germanic dialect".

In late 2003, Zbigniew Banasik of Poland proposed that the manuscript is plaintext written in the Manchu language and gave a proposed piecemeal translation of the first page of the manuscript.

Glossolalia

In their 2004 book, Gerry Kennedy and Rob Churchill hint to the possibility that the Voynich manuscript may be a case of glossolalia, channeling or outsider art.

If this is true, then the author felt compelled to write large amounts of text in a manner which somehow resembles stream of consciousness, either due to voices heard, or due to an urge. While in glossolalia this often takes place in an invented language (usually made up of fragments of the author's own language), invented scripts for this purpose are rare. Kennedy and Churchill use Hildegard von Bingen's works to point out similarities between the illustrations she drew when she was suffering from severe bouts of migraine—which can induce a trance-like state prone to glossolalia—and the Voynich manuscript. Prominent features found in both are abundant "streams of stars", and the repetitive nature of the " nymphs" in the biological section.

The theory is virtually impossible to prove or disprove, short of deciphering the text; Kennedy and Churchill are themselves not convinced of the hypothesis, but consider it plausible. In the culminating chapter of their work, Kennedy states his belief that it is a hoax or forgery. Churchill acknowledges the possibility that the manuscript is a synthetic forgotten language (as advanced by Friedman), or a forgery to be preeminent theories. However he concludes that if the manuscript is genuine, mental illness or delusion seems to have affected the author.

Hybrid language

In his book Solution of the Voynich Manuscript: A liturgical Manual for the Endura Rite of the Cathari Heresy, the Cult of Isis (1987), Leo Levitov declared the manuscript a plaintext transcription of a "polyglot oral tongue". This he defined as "a literary language which would be understandable to people who did not understand Latin and to whom this language could be read". His proposed decryption has three Voynich letters making a syllable, to produce a series of syllables that form a mixture of Middle Dutch with many borrowed Old French and Old High German words.

According to Levitov, the rite of Endura was the assisted suicide ritual for people already believed to be near death, famously associated with the Cathar faith (although the reality of this ritual is also in question). He explains that the chimerical plants are not meant to represent any species of flora, but are secret symbols of the faith. The women in the basins with elaborate plumbing represent the suicide ritual itself, which he believed involved venesection: the cutting of a vein to allow the blood to drain into a warm bath. The constellations with no celestial analogue are representative of the stars in Isis's mantle.

This theory is questioned on several grounds. First, the Cathar faith is widely understood to have been a Christian gnosticism, and not generally associated with Isis. Second, this theory places the book's origins in the twelfth or thirteenth century, which is several centuries earlier than most experts believe based on internal evidence. Third, the Endura ritual involved fasting, not venesection. Levitov offered no evidence beyond his translation for this theory.

Jim Child, a linguist of Indo-European languages, asserts that he has identified in the manuscript a "skeletal syntax several elements of which are reminiscent of certain Germanic languages", while the content itself is expressed using "a great deal of obscurity".

Cultural impact

Many books and articles have been written about the manuscript. The first facsimile edition was published in 2005, Le Code Voynich: the whole manuscript published with a short presentation in French. Because of heavy image cropping this does not quite constitute a proper facsimile edition.

The manuscript has also inspired several works of fiction, including The Voynich Cypher by Russell Blake, The Book of God and Physics: A Novel of the Voynich Mystery by Enrique Joven, The Voynich Enigma by Baz Cunningham, " The Book of Blood and Shadow" by Robin Wasserman, The Voynich Project: Nephilim Rising by James K. Rollins, Time Riders: The Doomsday Code by Alex Scarrow, Codex by Lev Grossman, and PopCo by Scarlett Thomas.

The manuscript was featured in Season 1, Episode 3 of the TV show Weird or What?.

The manuscript was featured in Season 2, Episode 2 of the National Geographic Channel's TV show Ancient X-Files.