Well, so much posts, I cannot answer all in detail ...
Jim Schulman wrote:If the Petrarchan scheme holds, the world card has to be eternity, regardless of any iconographic foibles in indivudal world card versions.
The Fame portion of the poem lists famous classical personages, the final part being philosophers, and ending with Xeno. Cleanthes and Chrysippus, the founders of the Stoic school, and of the ethics that permeates the poem. Given that these were never celebrities, fame is treated objectively, as belonging to the people to whom humanity owes the greatest debt.
I think, that ...
1. Cary-Yale (provisionally dating to 1441) had 16 trumps (so 5x16 cards) and imitated Chess. In Chess the Rooks are the most powerful cards, which seems to have had an influence on the later used numerology of Tarot (cards connected to the Rook function had a good chance to be very high in the numerology). I see, that FAME and JUDGMENT were used as rooks. FAME (somehow the ANGEL) was later highest TRUMP in Minchiate (with WORLD as the second highest trump), ANGEL=JUDGMENT were later highest TRUMP in Bologna.
The WORLD as an iconographic idea might have been not relevant in the time of Cary-Yale. We observe, that astronomical ideas start to dominate in the 1460s with Regiomontanus in Italy, with new world maps, with a first globe, with the Palazzo-Schifanoia in Ferrara.
For 1441 we have likely a strong influence of Petrarca's Trionfi interpretation.
I think, that PRUDENTIA was an own card in the Cary-Yale Tarocchi. Cary -Yale naturally contained 7 virtues (which is not proven, as the deck only exists in fragments).
Well ... my reconstruction of the Cary-Yale is naturally only a "reconstruction" ... and it might have errors.
But my argumentation for the Cary-Yale Tarocchi is like this:
Cary-Yale Tarocchi
with a larger and readable version at ..
http://a-tarot.eu/pdf/cy-jpg.jpg
Petrarca created 6 symbols (Love etc.) and Chess has six different figures (King, Queen etc.). The natural way to draw an analogy between both system to sort relate 6 elements of one side to six element on the other side.
a. The most important figure (though it is a weak figure at the board) is the King. Cause, if one King is gone, the game is over.
KING = ETERNITY = card Emperor
b. The weakest figure at the chess board is the pawn. The most weak figure in Petrarca's six elements is Love.
PAWN = LOVE = the pawn before the Queen = card Love
c. The Queen is also a very weak figure in medieval Chess. The second lowest figure in Petrarca's system is Chastity and somehow that fits with Queen.
QUEEN = CHASTITY = Empress
In Petrarca's text the virtues accompany Chastity. As Love only takes one card, but the system needs 16 figures, the 7 virtues get a pawn position.
7 OTHER PAWNS = virtues = 7 Virtues cards
d. We find two horses in the Cary.-Yale cards (Death and Chariot). The horses (= Knights) are Chess figures.
KNIGHT = DEATH = Cards Death and Chariot
e. An older Chess figure is the Elephant. The elephant was used in Chess history either as Chess-bishop or as a Chess-rook (I've for Italy the confirmation, that elephants were used as Rooks (maybe not everywhere in Italy and maybe not always). For the Trionfi system of Petrarca we have elephants drawing the chariot of Fame. The trunk of elephants was interpreted as a trumpet. We have trumpets at the Fame card and at the Judgment cards.
ROOK = FAME = cards Fame and Judgment
f. The Bishop is a slow and weak figure, Cessolis used the "advisor", the bishop itself was more common in England. France had a "Fou" and Germany possibly a "messenger". Other more military interpretation saw a "Bow-shooter". Some regions still knew the elephant.
The Bishop position is not clear. I see, that it might have been Pope and Popess, or Time and Hanging Man (Traitor as in the Charles VI) or Old man (Time ?) and Jester or Fool as in the German Courier-game.
BISHOP = TIME = unknown cards
2. that the 5x14 version (PMB-1 with 14 trumps only, provisioally given to 1452) hadn't a WORLD card. The highest card was JUDGMENT. The 5x14-structure suggests, that this deck-version didn't follow in extreme form the Chess interpretation.
3. The Charles VI (provisionally given to 1463) had - my opinion - also 16 trumps and an orientation towards Chess. All 16 trumps are present. For the older Petrarca idea ... I think, that it is partly lost or reinterpreted.
Charles VI Tarot
with a larger and readable version at ..
http://a-tarot.eu/pdf/ch-jpg.jpg
a. Emperor is still Emperor
b. The pawns are Love plus 7 virtues. But the earlier 3 theological virtues are replaced by Florentine virtues (Sun, Moon, Fool).
Card Sun presents a woman with a spindle ... it presents (my opinion) Florentine textile industry, the basic source of Florentine wealth
Card Moon (my opinion) presents two astronomers, and I think, that the astronomers present two real persons, Regiomontanus, who had arrived in Italy from Germany and Toscanelli, a Florentine astronomer and mathematician, who worked for the Medici. Toscanelli worked for the Medic, and I see the Medici as the commissioners of this deck. I think, that the card presents the Florentine pride on their local science.
Card Fool (my opinion) refers to the text "Morgante" by Luigi Pulci and the card presents somehow "Florentine literature". "Morgante" is a giant fool in the text (we see a giant Fool on the card) and he becomes acquainted to
the hero Orlando during a battle with stone-throwing actions (the card shows a stone throwing scene). Th text describes also the difficulties to find an suited armor for Morgante (we see, that the Fool stays half-naked). Morgante's weapon is a clapper of a bell (the card shows a string of bells as Fool's weapon).
Luigi Pulci was directly involved in the education of the young Lorenzo de Medici. During this educative time (1461 - 1463) the first 15 chapters of the Morgante were written. The latest version of the text had 28 chapters. A second giant Margutte appear in later chapters (the version with 23 chapters). In the development of Tarot we see in the later d'Este cards two giants (Fool and Magician). It's known, that the d'Este very early (1474) got the Orlando edition (with 23 chapters) from Pulci, and it (likely) inspired Boiardo to write his own Orlando version.
c. Empress (earlier for Chastity) is replaced the Pope.
d. The Rooks are now - in contrast to Cary-Yale - a "bad" destructed TOWER (new) and JUDGMENT (as already in present Charles VI). "Fame" - if it's inside this deck - became a cardinal virtue (which possibly meant "Prudentia", but was later interpreted as World)
e. The horses are as in Cary-Yale Death and Chariot. As the new "destructed Tower" in the Charles VI has relative clearly a "bad" connotation, which was not recognizable in the same sense recognizable in the Cary-Yale, this might indicate, that the Florentine logic saw a bad side (Emperor's side's? Pope's side ?) and a good side (Emperor's side's? Pope's side ?). Florence (especially the Medici) generally had a good relation to the Pope, maybe they identified the pope with the better side.
f. For the Bishop position we've now the final two cards "Hanged Man" (the traitor) as the "bad" adviser and "Father Time" as the "good" adviser. The "adviser" is usual in the Cessolis tradition.
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Back to your assumption "If the Petrarchan scheme holds, the world card has to be eternity, regardless of any iconographic foibles in indivudal world card versions. "
Well, if you've read my interpretation, it's clear, that my answer is "NO". "World" is generally is difficult, as we don't know, if this specific "idea" developed in the 1460s and was not part of earlier considerations. We have no early "word-lists" of the Tarot cards, we don't know the card titles before 1460 and even some time later till the 1490s we still don't know.
Fame and Judgment are the cards in the Cary-Yale model for the rooks.
Here we have a much earlier source, from Alfonso's chess book (1284):
The rules for "Chess with dice" are given in the translation of Alfonso the wise text with ...
And these movements should be known by all those who wish to play chess well because
without this they could not know how to do it nor understand the chess problems that men
desire to know because of the annoyance given them from the lengthiness of the regular game
when it is played out completely. Also they established for that reason the use of dice in chess so
that it could be played more quickly.
And they assigned the six, which is the highest roll of the die, to the king, which is the most
honored piece on the board. And the five to the fers. And the four to the rook. And the three to
the knight. And the two, to the fil. And the one, which they call ace, to the pawn.
Download address
http://www.mediafire.com/?nenjj1dimtd
6 = King ... as I had it for the Cary-Yale - Petrarca: Eternity
5 = fers = Queen ...
exchanged - Petrarca: Time
4 = Rook ... as I had it for the Cary-Yale - Petrarca: Fame
3 = Knight ... as I had it for the Cary-Yale - Petrarca: Death
2 = fil = Bishop ...
exchanged - Petrarca: Chastity
1 = Pawn ... as I had it for the Cary-Yale - Petrarca: Love
The use of dice for the chess game brought up the necessity to connect the dice results (1-6) with the chess figures, likely connected to some ideological ideas of "world interpretation".
For his own ideological or poetical reasons Petrarca (or somebody before or somebody after him) exchanged the position of the Queen with that of the fil (well, the clergy likely hadn't fun to be compared to the number 2; also the female role - an even that of a queen - in 14th or 15th century might have been considered lower as in the 13th, when the nobility and the knight-ideals had a stronger role).
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I see for the Cary-Yale Tarocchi (I think 1441) a clearer relationship to Petrarca's model, which in the Charles VI seems to have been partly forgotten.