TITLE: The Ymago Mundi and its World Map
DATE: 1410 
AUTHOR: Pierre d'Ailly [Petrus de Aliaco]
DESCRIPTION: A French prelate and cardinal, celebrated for his learning,
Pierre d'Ailly had great influence on the theological controversies of the
late 14th, early 15th centuries, especially during the council at Constance.
However, the cosmographical writings of this Archbishop of Cambrai, though
immensely popular during the 15th century, were almost forgotten after the
great discoveries of the early 16th century. Thanks to the research of scholars
such as Alexander von Humboldt, d'Ailly's influence on subsequent exploration
has received proper recognition and general acceptance. Overall, the text,
generally referred to as only Ymago Mundi, is actually a series of
twelve short treatises which contain geographical and astronomical speculations
and a reform of the calendar, all of which are bound up with four contributions
by Jean Gerson. The most important and influential treatise, called Tractatus
de Imagine Mundi, is the first one in the published volume. It was written
in 1410 when d'Ailly knew the astronomical work of Ptolemy through his Almagest,
but had not yet read his other work, Geographia, which was being
translated into Latin for the first time by Jacobus Angelus almost concurrently
with d'Ailly's production of his twelve treatises.
That d'Ailly was soon aware of the shortcomings of his Ymago Mundi
may, perhaps, be inferred from the appearance of a subsequent treatise.
Three years later, in 1413, the Cardinal, having acquired the new Latin
translation of Ptolemy's Geographia, began writing another geographical
work entitled, the Cosmographiae Tractatus Duo, or the Compendium
Cosmographiae (1414), especially to summarize the useful things contained
in Ptolemy's work. D'Ailly is, therefore, not only the last of the medieval
geographers before the Ptolemaic revival, but also the first of the Western
scholars who began that revival and thus had a great an influence on contemporary
thought. Besides these two treatises the Cardinal also drew a mappamundi
to illustrate his geographical ideas and wrote a short explanatory note,
the Epilogus Mappe Mundi, to accompany it.
While the original treatises were, of course, produced in manuscript form,
of which many copies are still extant attesting to its widespread popularity
and circulation, the best known form to modern scholars is probably that
of the printed (woodcut) edition of ca.1483 (Louvain) .
Cardinal d'Ailly's work is marked by great erudition, although he seldom
pronounces any positive opinion of his own. The learned prelate, otherwise
so orthodox, often allows a doubt to glimpse forth as to the geographical
dogmas of the Church. He expounds on controversial theories and supports
various arguments by quotations from famous Greek and Latin writers such
as Aristotle, Ptolemy, Seneca, Pliny, Augustine, Esra; and even Arab authors
like Averroes, Hali, Alfragan and Avicenna - obviously a remarkably well
read scholar. A singularly significant literary source frequently quoted
by d'Ailly, often verbatim, is the Opus Majus by Roger Bacon. Although d'Ailly
compiled his Tractatus de Imagine Mundi 140 years after the time
of Roger Bacon, the Cardinal chooses not to name a single medieval explorer,
whether Asiatic or African. That all knowledge of recent explorations should
have escaped his notice is hard to believe. Had not his own countrymen,
Jean de Bethencourt and Gadifer de la Salle, for instance, attempted to
conquer and evangelize the Canary Islands at the very beginning of the 15th
century ? The whole work, with the exception of a few Arabic citations,
mainly from Latin translations of the works of Avicenna and Averroes, might
have been composed a thousand years previously. Indeed, some of it had.
To take only one instance, his discussion of the Antipodes. In approaching
this controversy, d'Ailly states it with such clarity that we expect to
hear him assert the truth. But as a good theologian he finds himself confronted
by the arguments of St. Augustine, Cosmas and others, as well as the biblical
texts upon which it was founded. Overpowered by the weight of this authority,
d'Ailly takes refuge in hearsay.
Some say that it (i.e. the zone between the winter Tropic Capricorn and
the Antarctic circle) is a temperate and habitable as our own . . . However,
according to them, there can be no communication between the Antipodes and
us because of the impossibility of crossing the intervening Torrid Zone
and the Tropics. According to this opinion, the population of this region
would be ignorant of the teachings of Christ and the Apostles, which is
contrary to the sacred affirmation that ' their sound went into all the
earth and their words unto the ends of the world '. In the sixteenth chapter
of his City of God, St. Augustine refutes this opinion. However, certain
writers maintain that it is a fable and that the fourth zone (i.e. the southern
zone) is for the most part covered with water, and this view is supported
by highly probable reasons . . .
The reasons given, however, such as the claim that the elevation of the
sun there makes life impossible, presumably because it scorches the earth,
are highly improbable. For d'Ailly's personal opinion on this subject, or
for that matter on any other, one is hard put to find them within his writings.
Probably the most significant passages of d'Ailly's writings are those in
which he discusses the extent of the habitable globe. Some extracts from
these will provide some insight to his ideas of cosmogony (from the seventh
chapter of his Ymago Mundi ):
The earth is spherical and the Western ocean is relatively small. Aristotle
pretends, contrary to Ptolemy, that more than a quarter of the whole globe
is inhabited, and Averroes sustains the same opinion. The Stagyrite affirms
also that the extent of sea is small between the coast of Spain in the West
and the shores of India in the East. We are not concerned here with the
actual Spain, but with the Further Spain, which is Africa. Seneca
asserts that one can traverse that sea in a few days if the wind is favorable.
Again, Pliny teaches us that ships from the Gulf of Arabia can arrive in
a short time at Gades in the South of Spain. Whence we conclude that the
sea is not big enough to cover three-quarters of the globe. Esdras affirms
in his fourth book that six parts of the earth are habitable and inhabited
and that the seventh part alone is covered by the waters. The authority
of that work has been recognized by the saints, who have made use of it
for confirming the sacred verities. Beyond Thule, the last island of the
Ocean, after one day's sail the sea is frozen and stiff. At the Poles there
live great ghosts and ferocious beasts, the enemies of man. Water abounds
there, because those places are cold, and cold multiplies humors [or vapors].
In the forty-eighth chapter he tells us:
Thus the water runs from one Pole to the other forming a sea which extends
between the extremity of Spain and the beginning of India, of small width,
in such a way that the beginning of India comes to beyond the half of the
equinoctial line [i.e. in the other hemisphere], a situation very near to
that which the end of our hemisphere occupies.
In the forty-ninth chapter he uses another argument that he had borrowed
from Aristotle: "The west coast of Africa cannot be far removed from
the east coast of India, for in both those countries elephants are found."
Now the greatest interest of these and similar extracts from d'Ailly is
that they were of fundamental importance in governing the ideas of the last
of the medieval travellers, Christopher Columbus. However uncertain the
premises and unsound the conclusions may appear to a modern reader, they
were seized on by Columbus and his contemporaries and stimulated exploration
to the west and south. It has now been proved that practically the only
books on cosmogony that were familiar to Columbus were two, the Ymago
Mundi of d'Ailly, an edition published between 1480 and 1487, and the
Historia rerum ubique gestarum of Aeneas Silvius (Pope Pius II), published
at Venice in 1477. There are still preserved in the Library of the Colombine
at Seville the original copies of these books that were used by Christopher
and his brother Bartholomew, and their margins are filled from end to end
with remarks and notes in their own hands.
After his three historic voyages westward, Columbus in 1498, in letters
to his sovereigns, attempting to substantiate his claims of discovering
a new route to the Indies, proved that he was a man whose philosophical
foundation lay firmly in the Middle Ages. Not a discriminating scholar,
Columbus took his arguments ready-made from old fashioned, handy compendia,
but assumed an appearance of immense erudition by quoting passage after
passage from classical authors, both Greek and Latin, to prove that the
islands and mainland he had discovered are part of Asia. He refers incidentally
to d'Ailly as an authority supporting his view, but he does not reveal the
fact that almost every scrap of his classical learning is lifted bodily
out of the Cardinal's pages. This style of research produced two of Columbus'
major errors. One was underestimating the unknown waters to the west of
Europe because he adopted Marinus of Tyre's concept of the world through
d'Ailly's work; the other error Columbus' acceptance of Ptolemy's calculation
of distance around the world and, of course the size of a degree of longitude.
Thus, according to authorities such as Humboldt, Newton, and Vignaud, Columbus
in 1498 cribbed his views from d'Ailly who wrote in 1410, d'Ailly cribbed
from Roger Bacon whose work dates from 1267, Roger Bacon derives through
the Arabs from the Greeks. The most famous of the explorers of the new age,
in fact, drew none of his ideas directly from the newly recovered geographical
literature of the Greeks as did the true Renaissance thinkers like Peter
Martyr or Damian Goes. Therefore, according to some scholars, he discovery
of a new world was accomplished not with Greek or modern geographical concepts
but with medieval.
With specific reference to the writings of d'Ailly after his discovery of
Ptolemy's Geographia, it can be seen that the Cardinal was a critical
scholar. While he makes no attempt to incorporate or assimilate all of the
Ptolemaic technique into his own system, he is not slow to exploit it. Thus
he finds the 22 parallels of the Alexandrine climatic division too
cumbersome for his own use and reduces them to 12. Seven of these correspond
to seven of Ptolemy's climata; three, namely, Montes Barditi,
Raptum and Cattigara, are adopted from the ante-climata,
while the remaining two, Britain and Thule, pass through the post-climata.
Out of the thousands of places tabulated in the Geographia, d'Ailly
selects 353, the choice of which hardly commends itself from a geographical
standpoint, giving them their Ptolemaic latitude and longitude.
Whereas Meroe was formerly d'Ailly's most southerly outpost of the
oikoumene, now it is Montes Barditi qui meridionalem limitem nostre habitabilis
terminant, and to those he gives the latitude of 16°S Ethiopia is
similarly affected, receiving an ill-defined southern extension and made
to adjoin the hitherto unmentioned land of Agysimba. Again, whereas
in his first treatise d'Ailly describes Africa parem Europae longitudine,
tamen multo angustiorem, now he tacitly refutes it by admitting it to
be habitable as far as 16 degrees South and to extend still farther.
But it must not be imagined that the Cardinal followed his new-found authority
unquestioned. Occasionally he leans towards the arguments of Pliny and others,
and this, so it would seem, less from caprice than from an appreciation
of their intrinsic merit. Thus, for instance, in a passage made famous by
its association with the name Columbus, he demonstrates that the length
of the habitable earth is greater than that postulated by Ptolemy and points
out, as a corollary, that the commencement of India in the East could not
be very far distant from the western extremity of Africa. From this same
passage we learn that d'Ailly favors the concept of an open, rather than
an enclosed Indian Ocean, and, in consequence, a sea-girt Africa, although
this is nowhere stated categorically.
When all is said and done, however, d'Ailly is nothing if not deferential.
There is not a single idea in any of his geographical writings which cannot
be traced back, sooner or later to some impeccably orthodox source. At the
same time there is a keen sense of proportion pervading them all and an
obvious sincerity of intention. Thus, the Cardinal refuses to have anything
to do with such superstitions as the monstrous one-eyed giants, the Monoculi
, and the 'umbrella-footed' folk, the Sciapodae , who were commonly
reputed to be inhabitants of central Africa. Conversely, it is regrettable
that his preoccupation with classical erudition should have blinded him
to the importance of events nearer his own time.
After elaborating the various geographical concepts transmitted by Pierre
d'Ailly and noting his impressive list of sources, it is curious to take
note of the particulars of the mappamundi (drawn about 1410 perhaps after
an original by Roger Bacon of the 13th century) that accompanied both the
manuscript and printed editions of the Ymago Mundi. Unlike the more
provocative text, this circular map itself would probably never have stimulated
or inspired such exploration as that undertaken by Columbus. A world map
in the tradition of the medieval schematic zone-climate types, d'Ailly's
map is hemispherical (20.2 cm in diameter), and displays the entire habitable
world within the northern half. It is one of the earliest medieval maps
from Europe that was oriented with the north at the top. There is no attempt
at continental outlines or standard representation of landmasses. Instead
various countries are indicated by name only, with their relative positions
to one another thus conveyed. Also depicted, again by name only, are rivers
and mountain ranges. Exceptions in this regard being the Nile River, indicated
by wavy vertical lines extending from Alexandria to Meroe, the Mons
Athlas in Africa sketched half-heartedly near the Hesperides, and a
few wavy lines called Oceanus. Otherwise, there are only carefully
ruled climate zones and a few legends among the jumbled typography and no
display of monsters or mythical figures that could often be distributed
throughout other medieval and even Renaissance maps.
Again, the map by itself does not speculate or promote new geographical
ideas, however, given the concepts and ideas expressed in d'Ailly's text
and using the analogy between present-day radio, this seemingly blank map
with the provocative text and combined with an active imagination may have
been the most appropriate design for d'Ailly to have chosen. By omitting
any real or speculative coastlines, the author could leave the interpretation
of the textual material and speculation up to his reader.
LOCATION: New York Public Library
*Bagrow, L., The History of Cartography, p. 49, fig. 7.
*Bricker, C. et al, Landmarks in Mapmaking, pp. 14, 77.
*Kimble, G.H.T., Geography in the Middle Ages, pp. 23, 92, 208 212,
*Newton, A., Travel in the Middle Ages, pp. 17-18.
*Nordenskiöld, A.E., Facsimile Atlas, pp. 37-38.
World Encompassed, no. 16.