Disputed Statements

Yang Xi, Historical Figures

Standing Scholarly debate

Concerns Lifespan or Floruit End Year

Currently States 386

The source marks this year circa, its own approximate estimate rather than a fixed date.

Source Yang Xi (reference article), Wikipedia contributors tier 3

Yarsanism, Religions

Standing Scholarly debate

Concerns Origin Period

Currently States The current cycle of Yarsani religious history is dated by scholarship to the appearance of Sultan Sahak, placed provisionally in the fifteenth century CE.

Philip Kreyenbroek's own phrasing, perhaps in the fifteenth century CE, reflects the absence of an independently datable record for Sultan Sahak's life; other general accounts of the tradition place him in the late fourteenth century instead.

Source The Religious Textual Heritage of the Yarsan (Ahl-e Haqq), Philip G. Kreyenbroek tier 1

Yarsanism, Religions

Standing Scholarly debate

Concerns Adherents Today

Currently States Estimates for Yarsani adherents today vary widely, from roughly one million to as many as four million, concentrated in Iran with further communities in Iraq.

No independent census exists: Iran's own census does not enumerate Yarsanis as a separate religious community, and estimates come from the community itself, from outside researchers and from advocacy organizations, which do not agree with one another.

Source The Religious Textual Heritage of the Yarsan (Ahl-e Haqq), Philip G. Kreyenbroek tier 1

Yarsanism, Religions

Standing Scholarly debate

Concerns Origin Period Start Year

Currently States 1400

The year approximates Sultan Sahak's era, the point scholarship treats as the opening of Yarsanism's current cycle, since his life carries no independently datable record of its own. The century itself is disputed: provisionally fifteenth century CE in one scholar's own phrasing, against a late fourteenth century alternative that other general accounts give instead, both named elsewhere on this page. Fourteen hundred is set at the boundary the sources actually argue over. The tradition's own account of its origin is different in kind, framed around successive manifestations rather than a single dateable year, and is recorded separately on this page.

Source The Religious Textual Heritage of the Yarsan (Ahl-e Haqq), Philip G. Kreyenbroek tier 1

Yasna, Rituals

Standing Scholarly debate

Concerns Origin Period Start Year

Currently States -1000

The Yasna incorporates the Gathas, hymns attributed to Zoroaster himself, its own text says. Zoroaster's date is one of the most disputed in the study of religion: traditional Zoroastrian chronology places him around 600 BCE, but linguistic analysis of the archaic Gathic Avestan has shifted most modern scholarship toward a considerably earlier date, with roughly 1000 to 1200 BCE the current center of gravity and some estimates running as early as 1500 BCE.

Source A History of Zoroastrianism, Mary Boyce tier 1

Yatha Ahu Vairyo, Mantras

Standing Scholarly debate

Concerns Origin Period

Currently States Gathic Avestan

M. L. West's The Hymns of Zoroaster (I.B. Tauris, 2010) examines the linguistic evidence of the Gathas, the oldest Avestan hymns attributed to Zarathushtra, comparing their archaic grammar and vocabulary against other early Indo-Iranian texts to date the language itself to roughly 1500 to 1000 BCE. West sets that linguistic dating against the later Zoroastrian tradition's own chronology, which places Zarathushtra around 1000 to 600 BCE, a gap of centuries between what the language of the hymns supports and what the tradition transmitting them claims. Because the two lines of evidence, philological and traditional, do not converge on a figure, and a millennium separates the earliest and latest proposed dates, the atlas gives no single numeric window for these mantras' origin rather than presenting one scholarly position as settled fact.

Source The Hymns of Zoroaster, M. L. West tier 1

Yatha Ahu Vairyo, Mantras

Standing Scholarly debate

Concerns Origin Period

Currently States No numeric window is given: the dating of Zarathushtra is contested across a millennium or more

M. L. West's The Hymns of Zoroaster (I.B. Tauris, 2010) examines the linguistic evidence of the Gathas, the oldest Avestan hymns attributed to Zarathushtra, comparing their archaic grammar and vocabulary against other early Indo-Iranian texts to date the language itself to roughly 1500 to 1000 BCE. West sets that linguistic dating against the later Zoroastrian tradition's own chronology, which places Zarathushtra around 1000 to 600 BCE, a gap of centuries between what the language of the hymns supports and what the tradition transmitting them claims. Because the two lines of evidence, philological and traditional, do not converge on a figure, and a millennium separates the earliest and latest proposed dates, the atlas gives no single numeric window for these mantras' origin rather than presenting one scholarly position as settled fact.

Source The Hymns of Zoroaster, M. L. West tier 1

Yavanajataka, Esoteric Texts

Standing Scholarly debate

Concerns Era of Composition

Currently States The date is genuinely disputed. It presents itself as a verse rendering of an earlier prose translation from a Greek original, so any date fixes a stage of transmission rather than the material itself.

An influential reading of the closing verses placed the versification in the third century of the common era. Later work on the manuscript has argued that reading of the verses is mistaken, which unfixes the date without supplying an agreed replacement.

Source The Yavanajataka of Sphujidhvaja, David Pingree tier 1

Yayya ਯ, Alphabet Letters

Standing Scholarly debate

Concerns Origin Period

Currently States Sikh tradition credits Guru Angad, the second Guru, with giving the script its settled form in the sixteenth century

According To The Gurmukhi script

Two reference works give incompatible accounts. The Encyclopaedia of Sikhism (Harbans Singh, editor-in-chief, Punjabi University, Patiala, 1998) carries the Sikh tradition that Guru Angad, the second Guru (1504-1552), devised the script. The World's Writing Systems (Peter T. Daniels and William Bright, eds., Oxford University Press, 1996), surveying the paleography of Indic scripts, holds instead that the letterforms were already in mercantile use in the Punjab as one of the Landa scripts descended from Sharada, and that comparing those existing Landa forms against the Gurmukhi letters attested from Guru Angad's era shows a fixing and standardising of a repertoire already in circulation rather than an invention from nothing. Neither side has displaced the other because the two accounts read different kinds of evidence, a community's own historical memory against a comparative script lineage, and the atlas records both without adjudicating.

Source The Encyclopaedia of Sikhism, Harbans Singh (editor-in-chief) tier 2

Yayya ਯ, Alphabet Letters

Standing Scholarly debate

Concerns Origin Period

Currently States Historians of Indic writing place the letterforms earlier, in the Landa mercantile hands already used across the Punjab

According To The Gurmukhi script

Two reference works give incompatible accounts. The Encyclopaedia of Sikhism (Harbans Singh, editor-in-chief, Punjabi University, Patiala, 1998) carries the Sikh tradition that Guru Angad, the second Guru (1504-1552), devised the script. The World's Writing Systems (Peter T. Daniels and William Bright, eds., Oxford University Press, 1996), surveying the paleography of Indic scripts, holds instead that the letterforms were already in mercantile use in the Punjab as one of the Landa scripts descended from Sharada, and that comparing those existing Landa forms against the Gurmukhi letters attested from Guru Angad's era shows a fixing and standardising of a repertoire already in circulation rather than an invention from nothing. Neither side has displaced the other because the two accounts read different kinds of evidence, a community's own historical memory against a comparative script lineage, and the atlas records both without adjudicating.

Source The World's Writing Systems, Peter T. Daniels and William Bright (eds.) tier 1

Yazidism, Religions

Standing Scholarly debate

Concerns Adherents Today

Currently States Estimates of the global Yazidi population range from under five hundred thousand to over one million, concentrated in Iraq's Sinjar and Sheikhan regions with substantial diaspora communities in Europe formed largely after the Islamic State attack on Sinjar in 2014. The range reflects genuinely disputed counting, not merely unpublished data: pre-2014 Iraqi and Kurdish regional figures disagreed with each other before the attack, and the killing, abduction and mass displacement documented since have made any single current count harder rather than easier to establish.

Iraqi and Kurdistan Regional Government population figures for the Yazidi community have long diverged for reasons tied to the disputed status of Sinjar itself, and the atlas has not found a single figure independent scholarship treats as settled.

Source Yezidism: Its Background, Observances and Textual Tradition, Philip G. Kreyenbroek tier 1

Yellow, Colors

Standing Scholarly debate

Concerns Origin Period Start Year

Currently States 1666

According To Newtonian optics: the seven-colour spectrum

Isaac Newton's own account in Opticks (London, 1704) describes how he arrived at seven spectral colours: his earliest prism observations distinguished five bands, and he settled on seven, adding orange and indigo, by explicit analogy with the seven intervals of the musical octave, a numerological choice rather than a further optical finding. Reading Newton's own text against the continuous gradient a prism actually produces shows the seven-fold division is an interpretive choice about where to draw lines in that continuum, not a count nature supplies; observers from Newton's own time onward have disputed whether indigo is visually distinct from blue and violet at all. Any scheme in this atlas that treats seven colours as given inherits Newton's seventeenth-century analogy to the octave rather than an independent observation.

Source Opticks: or, a Treatise of the Reflexions, Refractions, Inflexions and Colours of Light, Isaac Newton tier 1

Yellow, Colors

Standing Scholarly debate

Concerns Origin Period End Year

Currently States 1704

According To Newtonian optics: the seven-colour spectrum

Isaac Newton's own account in Opticks (London, 1704) describes how he arrived at seven spectral colours: his earliest prism observations distinguished five bands, and he settled on seven, adding orange and indigo, by explicit analogy with the seven intervals of the musical octave, a numerological choice rather than a further optical finding. Reading Newton's own text against the continuous gradient a prism actually produces shows the seven-fold division is an interpretive choice about where to draw lines in that continuum, not a count nature supplies; observers from Newton's own time onward have disputed whether indigo is visually distinct from blue and violet at all. Any scheme in this atlas that treats seven colours as given inherits Newton's seventeenth-century analogy to the octave rather than an independent observation.

Source Opticks: or, a Treatise of the Reflexions, Refractions, Inflexions and Colours of Light, Isaac Newton tier 1

Yemen, Countries

Standing Scholarly debate

Concerns Legal Status

Currently States The 1991 constitution makes Islam the state religion and Sharia the source of legislation; since 2014 authority has been contested between rival administrations, and conversion from Islam and non Muslim worship carry severe risk.

Yemen's 1991 constitution, adopted at the country's unification, makes Islam the state religion and Sharia the source of legislation. Since 2014, when Houthi forces took the capital Sanaa and triggered a civil war, no single authority controls the country as a whole, and Yemen's formal 1991 legal framework operates unevenly and inconsistently across the resulting territorial divisions. Conversion from Islam and the practice of non-Muslim worship both carry severe risk throughout the country under this environment, a risk the State Department's report attributes both to the underlying legal framework's own severity, which predates the war, and to the absence of any single authority capable of moderating or consistently enforcing it during the war. Which authority controlling which territory applies the law how consistently is a live and shifting question tied to the unresolved civil war, and resolving Yemen's religious freedom situation more broadly depends on the conflict reaching a political settlement.

Source International Religious Freedom Report, United States Department of State, Office of International Religious Freedom tier 1

Yenghe Hatam, Mantras

Standing Scholarly debate

Concerns Origin Period

Currently States Gathic Avestan

M. L. West's The Hymns of Zoroaster (I.B. Tauris, 2010) examines the linguistic evidence of the Gathas, the oldest Avestan hymns attributed to Zarathushtra, comparing their archaic grammar and vocabulary against other early Indo-Iranian texts to date the language itself to roughly 1500 to 1000 BCE. West sets that linguistic dating against the later Zoroastrian tradition's own chronology, which places Zarathushtra around 1000 to 600 BCE, a gap of centuries between what the language of the hymns supports and what the tradition transmitting them claims. Because the two lines of evidence, philological and traditional, do not converge on a figure, and a millennium separates the earliest and latest proposed dates, the atlas gives no single numeric window for these mantras' origin rather than presenting one scholarly position as settled fact.

Source The Hymns of Zoroaster, M. L. West tier 1

Yenghe Hatam, Mantras

Standing Scholarly debate

Concerns Origin Period

Currently States No numeric window is given: the dating of Zarathushtra is contested across a millennium or more

M. L. West's The Hymns of Zoroaster (I.B. Tauris, 2010) examines the linguistic evidence of the Gathas, the oldest Avestan hymns attributed to Zarathushtra, comparing their archaic grammar and vocabulary against other early Indo-Iranian texts to date the language itself to roughly 1500 to 1000 BCE. West sets that linguistic dating against the later Zoroastrian tradition's own chronology, which places Zarathushtra around 1000 to 600 BCE, a gap of centuries between what the language of the hymns supports and what the tradition transmitting them claims. Because the two lines of evidence, philological and traditional, do not converge on a figure, and a millennium separates the earliest and latest proposed dates, the atlas gives no single numeric window for these mantras' origin rather than presenting one scholarly position as settled fact.

Source The Hymns of Zoroaster, M. L. West tier 1

Yeshe Tsogyal, Figures

Standing Scholarly debate

Concerns Historicity

Currently States Historicity debated

The Princeton Dictionary of Buddhism (2014) records that the eighth century Tibetan figure Yeshe Tsogyal is thinly documented outside the later treasure literature, terma texts said to have been hidden and later revealed, and that scholars examining that same body of literature hold differing positions on how much of the developed figure can be traced to a historical eighth century woman.

Source The Princeton Dictionary of Buddhism, Robert E. Buswell Jr. and Donald S. Lopez Jr. tier 1

Yi (Righteousness), Virtues

Standing Scholarly debate

Concerns Origin Period

Currently States The Five Constants as a formally fixed set of five, correlated with the five phases, wu xing, is credited to the Han dynasty scholar Dong Zhongshu; the individual virtues are independently attested earlier in the Analects and Mencius.

Source Sources of Chinese Tradition, Volume 1, Wm. Theodore de Bary and Irene Bloom (eds) tier 2

Yiddish, Languages

Standing Scholarly debate

Concerns Place of Origin

Currently States Jewish communities in German-speaking Europe. Which region is disputed: the Rhineland, or the Danube basin and Bavaria.

Two camps. Max Weinreich placed the formation of Yiddish in the Rhineland, and his account was standard for decades. Against it, Dovid Katz argued for the Danube basin and Bavaria on dialect grounds, and Alexander Beider has re-examined the dialect evidence and argued for a Bavarian and Bohemian origin for the eastern dialects specifically. Paul Wexler has proposed a more radical relexification account that most Yiddishists reject. The argument is live and turns on how the dialect data is weighted.

Source The YIVO Encyclopedia of Jews in Eastern Europe, Gershon David Hundert (ed.) tier 1

Yizkor, Prayers

Standing Scholarly debate

Concerns Origin Period

Currently States Yizkor is an Ashkenazi custom of the medieval Rhineland, grown out of the memorial books those communities kept after the massacres of the Crusades, and its communal portion still carries martyrs as a category today. The Encyclopaedia Judaica, 2nd edition (Berenbaum and Skolnik, eds., Macmillan Reference USA, 2007) records that while historians agree on this medieval Ashkenazi origin, they differ on how directly and how tightly to tie the prayer's rise to the 1096 massacres specifically, as opposed to the broader pattern of communal memorial-keeping across the period.

The Encyclopaedia Judaica, 2nd edition (Berenbaum and Skolnik, eds., Macmillan Reference USA, 2007) examined the origin of Yizkor, the Ashkenazi memorial prayer grown out of the medieval Rhineland communities' own memorial books kept after the massacres of the Crusades. Weighing the prayer's medieval Ashkenazi origin, on which historians agree, against how tightly its rise should be tied to the 1096 massacres specifically, it records the two as separable questions and finds the second undecided even though the first is settled.

Source Encyclopaedia Judaica, 2nd edition, Michael Berenbaum and Fred Skolnik (eds.) tier 1