COSMOGONY, COSMOLOGY, AND COSMOGRAPHY
In the preceding chapters the attempt has been made to show the origins
of a large part of the geographical lore of the Crusading epoch, the
sources from which we may learn about it, and where it stood in the
classification of learning. Now we may turn to our central theme: an
estimate of its actual substance and character.
This geographical lore was in no sense a unified body of knowledge and
belief. It was no more a unit than the religious thought of the age, or
the philosophy, astronomy, or morals. No one in the Middle Ages was
acquainted with all the facts and theories with which we shall have to
deal. Mental caliber, credulity, critical spirit, curiosity,
opportunities for research and for travel—these all varied widely with
the individual and determined his geographical concepts. Nevertheless,
though there was no unity of knowledge or belief in regard to specific
facts and no unity of point of view, the reader will not fail to
perceive, in the multitude of illustrative details which are presented,
that certain habits of thought and modes of expression were typical of
the epoch as a whole.
We must first discuss what was known and believed about the earth in its
larger relations, both in time and space, to the remainder of the
universe: opinions about the Creation, about the size and shape of our
terrestrial globe, about the influences exerted by the heavenly bodies
in determining or affecting geographical conditions upon its surface.
In the Introduction we explained why it is justifiable when dealing with
ancient and medieval geography to wander into the fields of cosmogony
and cosmography far beyond what are now regarded as the rightful limits
of geography. The present chapter, it is hoped, will make clear how
closely medieval conceptions of the present condition of the earth may
be connected with the medieval idea of the origins and nature of the
universe.
_GENERAL CHARACTER OF THE COSMOLOGY AND NATURAL SCIENCE OF THE PERIOD_
These difficult questions of cosmogony, cosmology, and cosmography
excited keen and vivid thinking because they lie on the border between
philosophy and theology. Men were more interested in attempting to solve
the insoluble mysteries of God and the universe than they were in the
world of nature immediately surrounding them. Immense and weighty
volumes were written in commentary on the Works of the Six Days, wherein
complicated arguments were elaborated with the finesse of scholastic
logic. In an age of faith, the religious enthusiasm of the architect and
artisan was transmuted into lofty cathedrals; that of the theologian
turned to the elucidation of the words of Scripture. To analyze these
words, to comment upon their minutest detail, to reveal the meaning that
presumably lay behind them was not only a work of piety and devotion but
an absorbing intellectual pastime for keen-witted thinkers. In more
concrete realms of natural science, the epoch was characterized by
little enough observation and creative thought. The teachings of Plato,
of Aristotle, and of the other available classical, Arabic, and early
Christian authorities were accepted and adopted uncritically. Very
different was the case with matters of cosmogony and cosmography. Here
was highly controversial ground where classical opinions were either
enthusiastically defended as casting light on Scripture or else bitterly
attacked as subversive of all truth.
THE CHARTRES GROUP: BERNARD SYLVESTER AND THEODORIC
We have seen in Chapter IV that the scholars of the Chartres group and
their pupils during the early twelfth century were endowed with peculiar
freedom of thought.[565] We note in the works of Bernard, Theodoric,
Adelard of Bath, William of Conches, and Bernard Sylvester a wide
departure from authoritative, orthodox theology. Theodoric, William, and
the two Bernards were readers of Chalcidius’ translation of the
_Timaeus_, of Macrobius, and perhaps of the writings of the great
ninth-century Platonist, John Scot Erigena, and all four felt the
powerful and seductive attraction of Platonism. Bernard Sylvester was
almost an out-and-out pagan, so much so, indeed, that his writings can
hardly be considered to lie within the pale of Christian theology.[566]
Theodoric and William tried harder to reconcile Platonism with the
teachings of the church, yet they did so in a rationalistic spirit
almost as abhorrent to strict orthodoxy as the paganism of Bernard
Sylvester. Theodoric expressly stated in his _De sex dierum operibus_
that he was going to explain the different Works of the Six Days
“according to physical principles,” and, following the letter of the
text,[567] he proposed to avoid all allegorical and moral
interpretations of Scripture. He believed that the best way to attain a
genuine knowledge of God was through an accurate understanding of what
God had created; and his explanation of the Creation, as we shall soon
see, was independent to a degree that amazes us in a writer of his time.
The following phrase is particularly significant where Theodoric extols
Moses’ treatment of the Creation in Genesis, saying: “He shows in a
rational manner the causes out of which this world has come into
existence and the order of time in which this same world was founded and
adorned.”[568] Hauréau writes of the first book of Theodoric’s
commentary: “Quant au premier livre, essai d’accord entre la Genèse et
le _Timée_, où l’on voit la religion et la philosophie conspirant à
résoudre le plus grave et le plus obscur des problèmes, le problème de
l’être, et se déclarant satisfaites de l’avoir résolu, ce premier livre
est ... de plus grand intéret.”[569]
ADELARD OF BATH AND WILLIAM OF CONCHES
In the _Quaestiones naturales_ Adelard of Bath gives vent to his scorn
for the mentality that blindly accepts beliefs merely because they have
the weight of authority behind them. In an extraordinary passage he
expresses these ideas thus (as translated and paraphrased by Professor
Haskins[570]): “‘It is hard to discuss with you,’ Adelard tells his
nephew [in the dialogue form of the _Quaestiones naturales_], ‘for I
have learned one thing from the Arabs under the guidance of reason; you
follow another halter, caught by the appearance of authority, for what
is authority but a halter?’... ‘If reason is not to be the universal
judge, it is given to each to no purpose.’[571]... While plants spring
from the earth by God’s will, this does not act without a reason.[572]
Human science must first be listened to ... and ‘only when it fails
utterly should there be recourse to God’ as an explanation.”[573]
William of Conches shows the same spirit where he insists that God acts
reasonably and not capriciously. He writes: “I am aware that some people
assert, ‘Though we do not know how this happens to be so, we know that
God can make it so.’ Wretched ones! What is more craven than to talk in
that way! Because God can do something is no sign that he actually does
it, nor any reason why he should do it, nor any reason why it is useful
that it should be done. For God does not do whatever he can do. To
employ a rustic expression: ‘God can make a calf out of a tree trunk,’
but does he ever do so?”[574] William apparently, unlike Theodoric,
thought that we are justified in avoiding irrational deductions from
Scripture by an appeal either to an allegorical interpretation or—what
is even more surprising at a time when the word of authority was usually
regarded as all-sufficient—to one’s own intellect: “We may begin our
reasoning from the authority of a master, but it should be perfected by
our own intellect.”[575]
CONCEPT OF NATURAL LAWS
Thus we see in the writings of Adelard, Theodoric, and William that the
approach was tentatively made toward the acceptance of the doctrine that
the universe is governed by natural laws. This doctrine, upon which the
edifice of modern science has been built, was also given partial
expression by other thinkers of the twelfth century. John of Salisbury
stated in effect that a sequence of causes gives rise to all things that
we may perceive with our senses, that we call these causes nature, that
nothing happens that is not the result of natural causation even though
the operation of this causation may be concealed from us; finally, that
the first cause of all is the will of God.[576] Alan of Lille clothed a
similar theory in allegory by personifying Nature in poetic form as the
representative of God and making her say: “Hear how in this universe, as
in a great city, order is established by the control of a majestic
government” (Moffat’s translation).[577] Much the same opinion was
expressed by an anonymous Scandinavian historian of the early thirteenth
century in his Latin _Historia Norwegiae_. After describing a terrible
volcanic upheaval from the bottom of the sea,[578] this writer adds that
many people regard such occurrences as prodigies, believing that the
world itself thereby gives warning of its own destruction.[579] Citing
Solinus, he goes on to set forth a purely physical explanation of
earthquakes and volcanic eruptions and adds that, though it may not be
possible to attain to clearsighted understanding of these phenomena and
of the major marvels of the world, they should not be looked upon as
prodigies nor considered as portents of universal cataclysm. On the
contrary they are, as it were, the servants of the all-knowing and
immutable founder of the universe to whose nature through some marvelous
process they have been placed in bondage.[580]
THE ORTHODOX TENDENCY
This sort of reasoning, however, was exceptional. In the mid-twelfth
century the appearance of Peter Lombard’s _Sententiae_ tended to divert
the theologian’s mind from Platonic and rationalistic studies and to
restore Church Fathers and Scripture to paramount authority.[581] We
look in vain for traces of the liberal attitude of the Chartres scholars
in the orthodox works of such prolific writers but perhaps less clear
thinkers as Peter Comestor, Giraldus Cambrensis, Gervase of Tilbury or
even Alexander Neckam. Giraldus’ _Symbolum electorum_[582] contains a
cosmography in verse which explains the Scriptural view of the Works of
the Six Days, and though we feel in this poem the influence of the
Peripatetic physics—which by this time were becoming universally
known—no attempt was made to expound the work of the Creation according
to physical laws. In the _Topographia Hiberniae_[583] Giraldus
illustrates his own attitude and the dominant attitude of his age by the
moral he draws from the story of eagles which occasionally fly so high
that they scorch their wings in the sun. This he compared to the
hopeless vanity of the man who tries to solve by reason or by knowledge
God’s riddles of the Creation and of the universe. Neckam also despairs
of explaining the mysteries of nature and asks, “Who may comprehend the
causes of things?” He describes thunder and lightning briefly but adds,
“The herald of the thunder fills the mind with terror and shows how
great is the creator thereof.”[584] Even Michael Scot, who enjoyed the
patronage of the enlightened, scientifically minded Emperor Frederick
II, attributed the fact that the waters of the spherical earth are held
in place to “a secret virtue ... beyond human ken and merit”
(Haskins).[585] Gervase of Tilbury reproduces uncritically in his _Otia
imperialia_[586] the ideas compiled by Peter Comestor regarding the
Creation. These were strictly correct opinions on which no suspicion of
heterodoxy could be thrown. Comestor went out of his way to express
opposition and antagonism to Platonic teachings.
EFFECTS OF INFLUX OF ARABIC SCIENCE
The conventional orthodox position, however, did not remain
unchallenged. The influx of Moslem Aristotelian lore at the end of the
twelfth century was held to be as menacing to the integrity of the
ecclesiastical tradition as any of the Platonic doctrines. But, though
stern prohibitions were leveled against the study of Aristotle and his
Arabic interpreters, the seductions of Aristotelianism could not be
resisted, and those elements of Peripatetic science which did not seem
utterly outrageous to Christian theology became the accepted and
authoritative science of the West in the mid-thirteenth century. William
of Auvergne, bishop of Paris, stood out valiantly against what he
regarded as teachings subversive of Christianity and of morals and in
his vigorous opposition to Aristotelianism even went so far as to adopt
many of the Platonic doctrines that had been popular among the scholars
of Chartres during the preceding century.[587] But translators like
Gerard of Cremona had done their work too well, and the enormous tomes
of Albertus Magnus were based to a large extent on the learning of the
Stagirite.
_THE CREATION_
The usual medieval treatise on the Works of the Six Days as described in
the Book of Genesis deals with many problems. Some of these are abstruse
and metaphysical: questions of the nature of God and the nature of time
and space. With these we are not concerned. Others are more concrete:
questions of the materials out of which God made the universe and of the
actual manner in which he worked.
PROBLEMS
For the sake of clearness let us state some of these questions as
follows, (1) The question of whether matter existed prior to God’s
creation of the world. That is to say, Did God fashion the universe out
of a pre-existing substance or did he make it out of nothing? (2) The
question of the manner in which the universe was fashioned after it was
once “created.” (3) The question of what furnished the light during the
first three days before the creation of the sun. (4) The problem of
whether the Six Days were actual divisions of time or merely
hypothetical divisions of the process of creation. (5) The question of
the nature of the waters above the firmament. (6) Various problems
arising in regard to the nature and location of Paradise and of the four
rivers flowing from Paradise. The first four problems are discussed
briefly in the present chapter. That of the waters above the firmament
is left for Chapter VIII (on waters), and that of Paradise for Chapter
XII (on regional geography).
THE PREËXISTENCE OF MATTER
(1) Did matter exist prior to God’s creation of the universe as we now
know it?
Consistently with his Platonism, Bernard Sylvester thought that God
formed the universe out of what he termed _materia primordialis_—a
chaotic mingling of the elements that had coexisted with God before he
converted the universe into its present shape.[588]
_The Orthodox View_
Theodoric of Chartres, on the other hand, explicitly denied the
coëxistence of the _materia primordialis_ with God before the Creation.
In this respect he showed himself far less divergent than Bernard from
the Christian point of view. The work of the first day, he said, was the
creation from nothing of the _materia_ of the universe, out of which
earth and heaven, fire and water and life were to be evolved.[589] This
_materia_ was the _hyle_, or chaos, of the ancient philosophers, he
explained, and was designated by Moses in the book of Genesis under
various names.[590] For example, when Moses wrote, “In the beginning God
created the heaven and the earth” (Gen. i, 1) the words “heaven” and
“earth” referred to chaos; when Moses wrote, “And the earth was without
form and void” (Gen. i, 2) the word “earth” referred to the primordial
mixture of land and water, a mingling of land that was not solid and of
water that was not liquid. Air and fire at that time were of about the
density of water.
Theodoric’s interpretation of the initial process of the Creation was
entirely in keeping with the views of more orthodox writers. Peter
Lombard, for instance, wrote as follows: “In the beginning God created
the ‘heaven,’ that is to say the angels, and the ‘earth,’ by which is
meant the material which composed the four elements. The latter were as
yet in the confused and formless condition to which the Greeks gave the
name of chaos, and this was before any day.”[591]
Peter Comestor also set forth an orthodox view of the Creation. In his
commentary on Genesis he revealed a love of the number three and
classified every thing possible into groups of three.[592] He pointed
out how Moses had avoided three errors. “First, that of Plato, who had
conceived of three coëxistent things, God, _ile_ (_hyle_, or chaos), and
time, and that the world was made out of _ile_; second, that of
Aristotle, who had conceived of two coëxistent things, the world and the
fashioner thereof (_mundus et opifex_); and third, that of Epicurus, who
had also conceived of two, space (_inane_) and matter in the form of
atoms, and that in the beginning natural processes had brought together
certain atoms to form water, others to form earth, and others to form
fire. Moses, however, had said that God alone was eternal and that the
world was created out of nothing, for there was no matter in existence
prior to the ‘Creation.’”[593] “In the beginning” meant in the beginning
of time as well as of matter, for time and matter were coëternal.[594]
_A Rational View_
William of Conches refused, on rational, physical grounds, to believe in
the possibility of a chaos preëxisting the Creation.[595] Having
accepted the classical doctrine whereby the four elements were arranged
in concentric spheres in order from heaviest to lightest,[596] he was
unable to conceive of a time when they could have been so intermingled
that they contradicted this law, though there may have been a time, he
conceded, when the earth was completely enveloped in a thick mantle of
water reaching very high and when air and fire themselves were denser
than they now are. Such a condition, William thought, was that described
in Genesis i, 2.[597]
PROCESSES OF THE CREATION
_Theodoric of Chartres’ Theory_
(2) How was the universe converted into its present form after God had
once created it?
Most commentators answered this either by saying or tacitly implying
that it was through the immediate operation of God’s will alone.
Theodoric of Chartres’ theory, therefore, is peculiarly interesting,
because Theodoric maintained that the formation of the universe resulted
from what we should now style a series of purely mechanical and chemical
reactions which began, once the composition of the _materia_ was
completed, on the first day. For its time this was an extremely
hazardous view, akin in some respects to the modern belief in the
sufficiency of physical and chemical action to produce practically all
observable phenomena.
Let us examine Theodoric’s theory in a little greater detail. In Genesis
i, 2, we read the words, “And the spirit of God moved upon the face of
the waters.” Theodoric explained that by the “waters” was meant the
whole of matter:[598] the “spirit of God” was that which was destined to
give order and form to the chaos, that is to say the “force which
fashioned” or “operated” (_virtus artifex_ or _virtus operatrix_). Plato
had called this force the World Soul, the Christians called it the Holy
Ghost,[599] and through its agency the evolution of the universe out of
chaos by physical processes was rendered possible.
Coincidently with the creation of the original _materia_ the universe
had assumed a rotary motion,[600] each complete rotation marking a day.
In the further unrolling of the universe, fire was the active element
(_artifex et efficiens causa_), earth the passive element, and air and
water stood as intermediaries between fire and earth. During the first
rotation, or first day, the fire heated and illumined the inferior
elements in such a manner as to cause the air to be released from them
(_aer ex inferioribus elementis spissatus_), and thus the atmosphere
came into existence.[601] On the second day the fire, by illuminating
the air, transmitted heat to the third element, water, which rose in the
form of clouds. Some of this vaporized water ascended so high that it
passed into the second heavenly sphere, where it became the “waters
above the firmament,” the firmament itself, according to Theodoric,
being the atmosphere.[602] So much water in this manner was absorbed out
of the original _materia_ that inevitably on the third day the earth
appeared like islands in the midst of the waters remaining behind.
Theodoric compared these to islands that are formed when water dries
after it has been spilled upon a table. Immediately the heat of the
atmosphere was mingled with the humors of the earth, and the latter
thereby received the power of producing vegetable life, herbs and trees.
On the fourth day the stars were formed out of the waters which had been
drawn above the firmament. On the fifth day the heat of the universe
brooded over (_incubuit_) the waters of the earth’s surface and gave
birth to fish and birds. Finally, on the sixth day, the life-giving heat
reached the earth; and from it the animals were created, including, of
course, man.[603]
_William of Conches’ Theory_
William of Conches’ theory of the Creation did not differ a great deal
from that of Theodoric, except that the _materia primordialis_ was not,
in his opinion, a chaotic mingling of the elements; for within it, he
thought, as we have already seen,[604] that the elements were arranged
in their proper order according to accepted classical laws of physics.
The lands were uncovered by the removal of the waters, though this took
place later in the process according to William than it did according to
Theodoric. William attributed the drying off of the waters partly to the
warmth of the stars (which were not formed until the fourth day) and
partly to the creation of the water and land animals on the fifth and
sixth days respectively.[605] In different portions of this primordial
land, when it was just in the act of emerging from the waters, fiery,
watery, earthy elements were present in varying quantities. This
condition gave birth to divers varieties of animals. Where the fiery
element was in excess, choleric animals, like the lion, came into being;
where the water element prevailed, phlegmatic animals, like the pig; and
the earthy element produced melancholic creatures like the ass and cow.
At the one and only place where the combination was absolutely equal,
man appeared. Woman, on the other hand, was made from a combination
almost like that of man but one in which the colder elements were very
slightly in excess, because the warmest of women by nature is colder
than the coldest of men! This last, an extremely free and heretical and
from our point of view unchivalrous theory, William retracted in his old
age.[606]
FUNCTION OF LIGHT IN THE CREATION
(3) What was the nature of the light which God made when he said, “Let
there be light”? Although Augustine had interpreted this passage
allegorically or mystically as referring to the creation of the world of
the angels,[607] he had also suggested that God might have created an
actual body of light corresponding to the sun. Bede[608] developed the
latter suggestion and maintained that there must have been a luminary
revolving around the earth as does the sun. In the twelfth century Hugh
of St. Victor and Peter Comestor, both of whom interpreted Scripture
more or less literally in this respect, followed Bede. Hugh maintained
that this original light was like a luminous cloud which rose in the
east and set in the west,[609] and Comestor spoke of it in much the same
terms.[610] Other theologians, however, refused to believe that such a
light could have actually existed and reverted to Augustine’s first
explanation that by the light was meant the world of angels as distinct
from the world of evil spirits below.[611] Peter Lombard referred to
both interpretations, though he appears to have been inclined to favor
the more literal and materialistic theory of Bede.[612]
With Robert Grosseteste light is made to play the leading part in the
entire process. In his unpublished _Hexaemeron_[613] and in the _De
luce_[614] he sets forth a theory of cosmogony which was derived in part
from the Moslems but in essentials was original.[615] We trust that the
following brief statement of the theory does not do violence to the
thought of Grosseteste as expressed in the _De luce_. He conceived of
light as the first corporeal form and also as giving form to the
_materia prima_ of the universe. By radiating through the unformed
_materia prima_ the light converted it into a sphere. Thereupon the
light made its way from the outer edge of the sphere towards the center.
As it passed through the various realms of the universe it diffused,
rarified, and purified the _materia_ of each, but with each stage of its
advance its powers were diminished and correspondingly the potentiality
of each successive realm of being purified was diminished. Thus thirteen
concentric spheres were produced, nine celestial spheres and four
spheres of the elements, and each of these was more complex, dense, and
impure than its neighbor above.
THE NATURE OF THE SIX DAYS
(4) Were the Six Days described in the book of Genesis actual divisions
of time? The words of the Bible seemed to be contradictory on this
point. From the words of Genesis alone one would gather that the
completion of the universe was accomplished in six days. On the other
hand, we read in Ecclesiasticus (xviii, 1), “He that liveth forever
created all things together” (Qui vivit in aeternum, creavit omnia
simul). According to Theodoric of Chartres[616] these two statements
referred to different events. The passage in Ecclesiasticus applied only
to the creation of the _materia primordialis_ on the first day. The
works of the succeeding days were the result of the automatic
development of natural processes by which the universe became as we now
know it. Belief in the reality of the duration of the Six Days was
shared with Theodoric by most commentators, such as William of Conches,
Hugh of St. Victor,[617] Peter Lombard, and Peter Comestor. Augustine,
however, had argued in a more abstruse vein that the “days” were not
actual units of time but that they represented merely so many distinct
operations in the work of creation.[618] And in our period Arnold of
Chartres urged that the Creation was carried out in one day and all at
once (_uno die et semel_).[619]
ETERNITY OF THE UNIVERSE
Though they differed in the details of interpretation, these theories
were all based on the fundamental acceptance of the axiom, deduced from
Scripture, that God created the universe out of nothing. In Chapter II
was explained the antagonism between this view and the Aristotelian
doctrine of an eternal, periodically re-formed universe. Certainly,
among Christians of our period, no one believed either in the eternity
or in the periodicity of the universe, although the existence and nature
of these concepts were well known. Both theories were set forth in
Seneca’s _Quaestiones naturales_,[620] in translations of Plato’s
_Timaeus_[621] and of Aristotle’s _Meteorology_[622] and _De generatione
et corruptione_,[623] and in translations from the Arabic such as the
_Liber introductorius in astrologiam_ of Abū Maʿshar[624] and the
pseudo-Aristotelian _Liber de proprietatibus elementorum_.[625] When
William of Conches specifically denied the possibility of more than one
deluge he may have had in mind the pagan association of Noah’s flood
with the Great Winter.[626] Certainly one of the primary objections of
the orthodox Christians to the acceptance of Aristotelian science during
the early years of the thirteenth century lay in the fact that Averroës,
the great interpreter of Aristotle, was firmly convinced that the
universe is eternal.[627] William of Auvergne also vigorously attacked
the Aristotelian theory as it found expression in Avicenna’s commentary
on the _Metaphysics_[628] and Robert Grosseteste leveled destructive
criticism against it in his _Summa super libros octo Physicorum_, a
commentary on the _Physics_ of Aristotle, and in other works.[629]
BERNARD SYLVESTER’S ACCOUNT OF THE CREATION
Before leaving this aspect of the subject, a few words should be said
about two other accounts of the Creation that found literary expression
in Western Europe during our period. Very dissimilar, these two accounts
are akin only in the circumstance that they were both based upon the
mythology of an older age and that, though written by Christians,
neither referred in any way to the Scriptural story. One was the
remarkable allegory in Bernard Sylvester’s _De mundi universitate_, the
other the Icelandic myth of the Creation as recorded in the _Edda_ of
Snorri Sturluson.
In the _Megacosmus_, or first part of the _De mundi universitate_,
Bernard tells us of the confusion of matter in the eternal ages that
preceded the “Creation.”[630] Nature, personified, laments to “Nous,” or
Providence, about this confusion and demands that the universe be put
into an orderly condition: “Nous,” moved by the appeal, carries out the
task, separating the elements, arranging the nine hierarchies of angels,
placing the stars in the firmament and regulating their orbits, ordering
the four winds, and, finally, fashioning the earth in the midst of the
universe. The last process gave Bernard occasion to digress and to tell
of the riches and beauties of this earth.
The _Microcosmus_, or second part of the book, goes on to relate the
story of the creation of man. “Nous” sees the barren desolation of an
inanimate world and orders Nature to undertake the work of peopling it.
With the aid of Urania, goddess of the stars, Nature seeks for Physis,
goddess of life, whom she finds in the terrestrial paradise after Urania
has conducted her on a long journey through the heavenly spheres. Here
she tells Physis her mission; and Physis carries out the fashioning of a
human body, in which the soul is then established. Thus was man created.
No comment is needed to bring out the pagan character of this account,
wherein the Six Days are not even mentioned! It would probably be wrong,
however, to assume that this work of literary imagination, any more than
Snorri’s graphic record of the beliefs of his forefathers, represents a
formulated and accepted doctrine of its author.
THE ICELANDIC ACCOUNT
The Icelanders were converted to Christianity in the mid-eleventh
century, and the mythology of their pagan days still remained fresh in
their minds and hearts during the period we are studying. The old gods
were looked upon with affection, and the old story of the Creation was
remembered with sympathetic understanding. The Icelandic myth of the
Creation is one of great beauty and vigor. In it is revealed the
impression made upon the minds of a northern people by struggles against
the cold and stormy darkness of the subarctic winter. The outline of the
story, which is worked out in much detail in the _Eddas_, is about as
follows.[631]
In the beginning a great abyss lay between the icy rivers and the
drizzling rains and blasts of wind of the north and the blazing heat of
the south. This was before heaven and earth and sea were made. “And
Fimbultyr said: Let the melted drops of vapor quicken into life, and the
giant Ymer was born in the midst of Ginungagap[632] [the abyss]. He was
not a god but the father of all the race of evil giants. This was Chaos.
“And Fimbultyr said: Let Ymer be slain and let order be established. And
straightway Odin and his brothers ... gave Ymer a mortal wound, and from
his body they made the universe; from his flesh, the earth; from his
blood, the sea; from his bones, the rocks; from his hair, the trees;
from his skull, the vaulted heavens; from his eyebrows, the bulwark
called Midgard. And the gods formed man and woman in their own image of
two trees, and breathed into them the breath of life. Ask and Embla
became living souls, and they received a garden in Midgard as a dwelling
place for themselves and their children until the end of time. This was
Cosmos” (Anderson).[633]
_MACROCOSM AND MICROCOSM_
All medieval accounts of the Creation culminate in the creation of man,
as modern outlines of evolution conclude with man’s evolution from lower
forms of life. Christian theology taught that the universe itself was
made for man, a view that persists even to this day. Grosseteste
asserted that when man “no longer requires the processes of generation
and corruption which the movements of the heavens cause, the heaven
itself will cease to move and time will be no longer.”[634] Rupert of
Deutz explained that mountains were placed upon the earth to protect
human beings against the winds.[635] But if the universe and all its
parts were made for man, medieval thinkers held, with the Stoics of
antiquity,[636] that man himself was a lesser universe (_minor mundus_),
or microcosm, comprising all the elements both physical and spiritual
which constitute the greater universe, or macrocosm.
[Illustration:
EXPLANATION OF FIG. 5—The human figure here represents the microcosm
in the midst of the universe. The heads of the animals give rise to
the winds, which Hildegard believed controlled the movements of the
celestial bodies (see p. 171). The blast originating in the human
head at the right and moving in a counter-clockwise direction runs
opposite to the movement of the firmament. “This blast did not give
forth his breath earthward as did the other winds, but instead
thereof it governed the course of the planets” (_Liber div. op._,
in: Migne, _Pat. lat._, vol. cxcvii, col. 791, as cited by Singer,
_op. cit._ p. 28).
In another miniature from the same manuscript (fol. 9 ro) shown in
Singer, _op. cit._, pl. VII, the universe is revealed in much the
same manner with the human figure as the microcosm. There is also
represented the macrocosm, as a larger figure standing behind and
holding the sphere of the cosmos; only its head, feet, and hands
appear.
FIG. 5—The macrocosm, the microcosm, and the winds, from a miniature
in an illustrated codex of Hildegard of Bingen’s _Liber divinorum
operum_ in the Municipal Library at Lucca, fol. 27 vo. (Redrawn, by
permission, from Singer, _Scientific Views and Visions of Saint
Hildegard_, 1917, pl. VIII.) For explanation, see bottom of opposite
page.
]
The doctrine of man as the microcosm had its roots far back in
antiquity. Medieval writers from the time of Isidore elaborated upon it
with detail and ingenuity. In the literature of our period it occurs in
many a passing comparison of the phenomena of nature with the human
body, such as that of the _De imagine mundi_ where rivers are compared
with blood vessels.[637] It forms an important element in the cosmology
of Bernard Sylvester’s _De mundi universitate_[638] and of Herrad of
Landsperg’s _Hortus deliciarum_.[639] Hildegard of Bingen’s writings are
full of similes and medical recommendations based upon it (Fig. 5).[640]
In her _Subtilitates_ the abbess says: “In the creation of man from the
earth other earth was taken, and all the elements served man because
they perceived that he lived; both the elements and man worked together
to each others’ advantage in all relationships.”[641] The thought is
expressed more clearly in the _Causae et curae_: “Oh, man! Look at man,
for man has in himself heaven and earth and all other things that are
created, and his form is one and in him all things lie hidden.”[642] To
illustrate the detail in which Hildegard worked out this theory we may
do no better than to quote from Thorndike’s summary. “She compares the
firmament to man’s head, sun, moon, and stars to the eyes, air to
hearing, the winds to smelling, dew to taste, and ‘the sides of the
world’ to the arms and sense of touch. The earth is like the heart, and
other creatures in the world are like the belly. In the _Liber divinorum
operum_ she goes into further detail.... From the top of the cerebral
cavity to the ‘last extremity of the forehead’ there are seven distinct
and equal spaces, by which are signified the seven planets which are
equidistant from one another in the firmament. An even more surprising
assumption as to astronomical distances is involved in the comparison
that as the three intervals between the top of the human head and the
end of the throat and the navel and the groin are all equal, so are the
spaces intervening between the highest firmament and lowest clouds and
the earth’s surface and center.... As the heart is stirred by emotion,
whether of joy or of sorrow, humors are excited in the lungs and breast
which rise to the brain and are emitted through the eyes in the form of
tears. And in like manner, when the moon begins to wax or wane, the
firmament is disturbed by winds which raise fogs from the sea and other
waters.”[643] The preface to the _Subtilitates_ contains another
discussion of the microcosm in the course of which the stones of the
earth are likened to bones and it is pointed out that the earth has
sweat, humors, and other by-products of the body.[644] Much of the
argument of the _Causae et curae_ is based upon the assumption that the
very diseases of man have their counterparts in the facts of the
macrocosm.
_SHAPE, MOVEMENTS, AND SIZE OF THE EARTH_
When once created, what form did this universe take, and the earth
within it?
SPHERICITY OF THE UNIVERSE
Nearly all the authors of our period appear to have shared in the belief
that the universe is a sphere and that the earth is situated in its
center. Lambert of St. Omer says in his _Liber floridus_: “We say the
earth is the center, that is, the point in the middle of the sphere.”
“For the earth is located as a central point in the midst of the
celestial circle through which the sun passes.”[645] Robert Grosseteste
stated that the sphericity of the universe was necessitated by the
nature of the substances composing the heavenly bodies and that it could
be proved by simple astronomical observations.[646] There is, perhaps,
an echo of Pythagorean mathematical doctrines in the exposition which we
find in the _Image du monde_, that the world is round since God desired
it to be so, because roundness is the most perfect of all forms.[647]
Al-Farghānī, whose work was translated more than once during our period
and formed the basis of much that is found in John of Holywood’s _De
sphaera_,[648] had said that there was no difference of opinion among
learned men that the universe was a sphere. That the earth is in the
center of the heaven, he asserted, was shown by the fact that half the
heaven is always visible from all parts of its surface.[649] The author
of the _De imagine mundi_ had also thought the same way:[650] he
compared the universe to a ball, or to an egg of which the shell
corresponds to the upper heavens, the white, to the upper air, the yolk,
to the lower air, and the _pinguedinis gutta_, or drop of grease in the
center, to the earth.[651] Gervase of Tilbury,[652] who borrowed the
idea from Comestor,[653] and the author of the _Image du monde_[654]
make similar comparisons, although Peter Abelard,[655] William of
Conches,[656] and Daniel of Morley conceived of the four parts of the
egg as corresponding exactly to the four elements.[657] Michael Scot
compared the earth, surrounded by water, to the yolk of an egg and the
spheres of the universe to the layers of an onion.[658]
In her _Causae et curae_, on the one hand, and in her _Scivias_ and
_Liber divinorum operum_, on the other, Hildegard of Bingen makes
contradictory statements in regard to the position of the earth in
relation to the heavenly spheres. Scientific consistency was not,
perhaps, the ascetic abbess’s strongest quality, and too much emphasis
should not be laid upon contradictions found in the writings of one who
believed herself to be favored by special divine revelations. The
passage in the _Causae et curae_, however, diverges so widely from
current medieval opinion that it is worth translating. “The earth,”
writes Hildegard, “is of moderate size and is near the base of the
firmament, because if it were in the center of the firmament, then it
would have to be larger; and even so it would easily fall and be
shattered to pieces, had it the same expanse of air beneath that there
is above.”[659] On the contrary, in her _Liber divinorum operum_ she
tells how she saw in a vision the universe as a wheel[660] and that “in
the midst of the air the earth was placed in such a way that the air
measured an equal distance above the earth, below the earth, and on
either side of the earth.”[661]
SHAPE OF THE EARTH
Most writers of the Crusading age thought the earth also was a sphere,
though there was less unanimity in this belief. The _De imagine mundi_
calls it a sphere, whence comes the term _orbis_.[662] William of
Conches[663] furnishes us with the Aristotelian proofs of sphericity. If
the earth is flat, he says, it would be day at the same time in the
farthest east as in the farthest west. Certain stars are visible in one
latitude that cannot be seen in another, and this would not be the case
if there were no curvature from north to south.[664] John of Holywood,
following Al-Farghānī, gave two proofs that the earth is round and two
that the water is round.[665] That there exists a swelling or curvature
of the earth (_tumor terrae_), he says, is shown by the difference in
the time of eclipses between places in the east and west as well as by
differences in the visibility of stars.[666] The curvature of water
surfaces is demonstrated by the fact that a person standing at the foot
of a mast is frequently unable to see objects visible to somebody at the
masthead. Furthermore, since water is a homogeneous body, all parts of
it must partake of the nature of the whole. Therefore it follows that
because a drop is round, the mass of the waters of the earth must also
be spherical.[667]
Gervase of Tilbury has been accused of believing that the earth is
square, though the evidence in the text of the _Otia imperialia_ on
which this accusation is based is very slender; and other texts would
seem to support the opposite contention, that he accepted the theory of
sphericity.[668]
Two passages in the _Causae et curae_ of Hildegard can apparently be
explained only on the supposition of a flat earth.[669] Hildegard seems
also to have been haunted by the old belief that bulked so large in the
imagination of Cosmas Indicopleustes,[670] the belief that the earth
rises into an immense mountain in the north.[671] She asserted that this
mountain prevented the light of the east from penetrating the darkness
of the north and the darkness of the north from obscuring the light of
the east. On the other hand, in her visions the abbess more than once
saw the earth as a globe.[672]
In the writings of the mystic Hugh of St. Victor we have a typical
medieval allegorical interpretation of the words of Scripture regarding
the earth’s form, with instructions as to how a map of the world ought
to be made.[673] Hugh compares the _orbis terrae_ to an “oblong circle,”
or oval, drawn around the ark, touching each corner. An oval shape was
necessitated by the rectangular ground plan of the ark. Within this oval
the _mappa mundi_, or map of the world, is to be drawn, with the front
of the ark facing the east, and its rear, the west. In the segment
formed to the east, between the ark and the circle, is Paradise; in that
to the west the resurrection will take place; the chosen will go to the
right, and the damned to the left into Hell, which forms the segment
toward the north. Beyond this “oblong circle” another circle is to be
drawn to show the zones, and the space between the two is the
atmosphere.
One hesitates to draw conclusions from this as to what shape Hugh
imagined the earth to be; probably he himself had no very definite
theory. The picture which his description seems to invoke in our minds
is that of a flat oval earth covered by an ovoid heaven, and certainly
it is in every respect inconsistent with belief in a spherical earth.
IMMOBILITY OF THE EARTH
However men may have thought about the shape of the earth, there was no
questioning the fact that it stands immobile and firm. Doctrines like
that of the Pythagorean Philolaus had no place in medieval thought.[674]
The ignorant, nevertheless, were often puzzled by the problem of what
supports the earth. The author of the _De imagine mundi_ was content
uncritically to explain that no fulcrum or support is necessary for this
purpose but that the “divine power” is all-sufficient.[675] He quoted
the one hundred and third Psalm: “Who hast founded the earth upon its
own bases: it shall not be moved for ever and ever.”
Theodoric of Chartres, Adelard of Bath, and John of Holywood, on the
other hand, adduced proofs of the immobility of the earth which had been
derived indirectly from Aristotle. Theodoric asserted[676] that the
earth does not gain its compactness either from its inherent nature,
because earth is actually observed on occasions to become mingled with
air; or from the weight of the overlying atmosphere and sphere of fire,
because these have no weight. What, then, keeps it from flying to
pieces? Here Theodoric appealed to the Peripatetic reasoning that the
circular motion of the heavens necessitates the existence of a solid and
immovable body in the center.[677] All heavy bodies acquire their
_substantia_, or solidity, from the motion of light bodies; and
conversely light bodies derive their motion from heavy bodies.
The _Quaestiones naturales_ of Adelard of Bath is in the form of a
dialogue between Adelard and a nephew who asks questions. The nephew was
much puzzled by the fact that, whereas heavy objects like rocks need a
piece of wood or other support to hold them up in the air, the earth as
a whole, much the heaviest of all, requires no such support.[678]
Adelard replies first that the earth does not fall because there would
be no utility in its doing so; then he proceeds to show by a rational
argument (_rationabiliter_) why the earth does not need a support. The
principal quality of earth he says, is heaviness; heavy bodies naturally
seek the lowest position (_infimum_); the lowest position of a spherical
body like the universe is its center—though why this latter proposition
is so, Adelard fails to make clear. At all events, the earth tends to
seek the center of the universe, just as a stone thrown into an
imaginary hole piercing the center of the earth would come to a halt
there.[679] Since the center of the universe is one point, not several,
the earth forms a single unit, not several; and for these reasons,
moreover, the earth is stable and immobile.
John of Holywood explained[680] the same thing more briefly than Adelard
by simply stating that the immobility of the earth is due to its weight,
since it is the nature of all heavy things to seek the center of the
universe and since the earth is the heaviest of all elements. Both
Adelard’s and John of Holywood’s arguments suggest the Aristotelian
doctrine of an equilibrium of forces around the center of the globe,
though this doctrine is not cited in so many words. Like most medieval
writers, Adelard and John seem only partially to have understood the
obscure texts from which they derived their proofs and to have left out
many links in their chains of reasoning.
SIZE OF THE EARTH
Though the geocentric hypothesis prevailed in the Middle Ages, there is
plenty of evidence to show that the smallness of the earth in relation
to the heavenly bodies was understood.[681] William of Conches had
thought that the sun was eight times as big as the earth.[682] In the
_Image du monde_ this theme is elaborated:[683] we are told that it
would take more than a hundred years for a rock to fall from the
heavens; that the earth is like a tiny star in comparison with the
immensity of the cosmos and is one hundred and sixty-six and
three-twentieths times smaller than the sun.[684] John of Holywood
quoted Alfraganus (Al-Farghānī) to the effect that the smallest fixed
star is larger than the earth[685] but that the dimensions of such a
star are as but a point in the firmament. He argued that the extreme
smallness of the earth is proved by the fact that it is possible to see
the middle of the firmament (_medietas firmamenti_) not only from the
center of the earth but also from the earth’s surface.[686] His
argument, which certainly proves nothing as it stands, is evidently a
confused reflection of Ptolemy’s reasoning in the _Almagest_.[687]
As to the actual size of our planet various figures were occasionally
quoted. The _De imagine mundi_[688] gives Posidonius’ estimate of the
circumference as 180,000 stades, or 12,052 miles (_duodecies mille
millaria et quinquaginta duo_). The _Image du monde_,[689] however,
gives 20,428 miles. Eratosthenes’ 252,000 stades appears in Lambert of
St. Omer’s _Liber floridus_[690] and John of Holywood’s _De
sphaera_.[691] In the latter work it is cited on the authority of
Ambrose, Macrobius, “et Eristenis philosophorum,” along with a brief
account of the great Alexandrian geographer’s method of measurement.
_ZONES, THE ANTIPODES, AND “CLIMATA”_
The surface of the terrestrial sphere, surrounded as it is by the
heavens, is naturally subjected directly to the influence of the
heavenly bodies. We must now examine those general phenomena of the
globe as a whole which were conceived to be consequences of the earth’s
shape and position in relation to the remainder of the universe,
postponing for a later chapter the study of the more local features of
the _oikoumene_ (or habited quarter), which also result from the same
circumstances.
ZONES
The most primitive observation reveals the fact that the heavenly bodies
in their course through the sky revolve around two points and mark out
certain circles. Very elaborate and often admirable discussions of the
celestial poles, Arctic and Antarctic circles, equator, tropics, and
ecliptic, are to be found in the numerous astrological and astronomical
works of our period.[692] The study of these matters was already a
highly developed science, but except in its geographical bearing it does
not fall within our province.
We saw in Chapter I that ancient astronomers had drawn imaginary circles
around the terrestrial sphere corresponding to the circles of the
heavens and had designated these lines as the boundaries of zones on the
earth’s surface.[693] The classical theory of five zones, divided from
each other by parallels of latitude, was accepted by the geographical
writers of the twelfth and early thirteenth centuries, although, as in
classical times, opinions diverged widely regarding the characteristics
of each zone. All, however, believed that the two polar caps were cold
and that the equatorial regions were hot. For example Bernard Sylvester
says in his _De mundi universitate_:[694] Nous, or Providence,
“encompassed the earth with five parallels; on the one hand the extremes
are frozen, on the other the central portions are hot. Also she made
temperate two zones by placing on both sides of them the coldness of the
extremities and the course of the sun over the midst of the earth.”
UNINHABITABILITY OF POLAR CAPS AND EQUATORIAL ZONE
Furthermore, a widely prevalent but not universal theory made the polar
caps and equatorial zones not only cold and hot but also uninhabitable.
The author of the _De imagine mundi_[695] and Gervase of Tilbury[696]
plagiarized what Isidore had written on this subject.[697] They called
the five circles separating the zones and the zones themselves from
north to south, respectively, _septentrionalis_ (our Arctic Circle and
North Polar zone), _solstitialis_ (our Tropic of Cancer and North
Temperate zone), _equinoctialis_ (our Equator and Torrid zone),
_brumalis_—or _hyemalis_ according to Gervase—(our Tropic of Capricorn
and South Temperate zone), and finally _australis_ (our Antarctic Circle
and South Polar zone). Of these they thought that only _solstitialis_
was habitable. William of Conches likewise believed[698] in
uninhabitable torrid and frigid zones, though he rejected the theory
that in the heavens above the sphere of the moon there are qualities of
heat and cold corresponding to those of the terrestrial zones.
AUSTRAL CONTINENT AND ANTIPODAL REGIONS
Speculation was rife as to what lay beyond the equatorial zone and in
those mysterious parts of the earth of which man had no knowledge.
Rumors and conjectures of an austral continent and of antipodal regions
figure widely in the geographical literature of the age. A fourth
continent beyond the equatorial ocean (or Mare Rubrum) is shown on all
the Beatus maps. It is represented as a strip of land along the
southernmost edge of the earth (see Figs. 2 and 4, pp. 69 and 123,
above). A legend, taken from Isidore, informs us on the St. Sever map
that “In addition to the three parts of the world, there is a fourth
part beyond the ocean in the midst of the south and unknown to us on
account of the heat of the sun. Within its confines the antipodeans are
fabulously said to dwell.”[699] The Osma Beatus map locates the
_skiapodes_, or sun-shade-footed men, here (see Fig. 4). Confusion
between true antipodal regions on the opposite side of the world and an
austral continent lying south of the equator was not uncommon in
antiquity and during the Middle Ages.[700] Belief in the latter did not
necessarily involve belief in a spherical earth, and it has been argued
that the Roman cartographers (whose maps may have inspired Beatus)
showed such a fourth continent south of the equator, even though they
did not deem the question of the sphericity of the world worthy of
serious consideration. The Beatus maps themselves may easily be
reconciled with an implicit belief in a flat world disk.
While this may be true of the Beatus maps, it cannot be said of the
_mappamundi_ of Lambert of St. Omer or of references to the antipodes
elsewhere in the literature of our period where it is impossible to
question the conviction in the cartographers’ or writers’ minds that the
earth is a sphere.
On Lambert’s map the austral continent occupies half of the circle of
the earth. A long legend explains,[701] in terms similar to those of the
St. Sever Beatus map, that this region is unknown to mankind because of
the sun’s heat; that philosophers say the antipodeans dwell here; and
that winter prevails during our summer. In addition to the austral
continent, Lambert indicates without a shadow of doubt his faith in the
existence of other antipodal regions. A large island on the western
margin of his map is labeled, “Here dwell the antipodeans, but they have
a different night and opposite days.”[702] We know from other parts of
the _Liber floridus_ that Lambert was strongly influenced by Macrobius.
A Macrobian sketch of a spherical world showing the five zones is
inserted in the Ghent and other manuscripts. This reference to the
antipodes can only apply to the unknown regions on the opposite side of
the globe, beyond the meridional ocean which, as we have seen in Chapter
I, had been described by Crates of Mallos and popularized in Macrobius’
_In somnium Scipionis commentarius_ and in Martianus Capella’s _De
nuptiis Philologiae et Mercurii_. Belief in a spherical world is
essential to belief in these theories.
THE CRATESIAN THEORY
Crates of Mallos’ conception of the arrangement of the world, introduced
to Western knowledge through the works of Macrobius and Capella, was
well known in our period. William of Conches, Adelard of Bath, and
Bernard Sylvester all show the influence of the Crates-Macrobian system
in their belief in a great equatorial ocean.[703] Giraldus Cambrensis
and the author of the _De imagine mundi_, by their explanation of the
causes of the tides, make it plain that they accepted the same opinion.
Geoffrey of St. Victor gives a clear exposition of it in his
_Microcosmus_.[704] Robert Grosseteste adopts it in his _De sphaera_,
explaining carefully the two seas that encircle the earth and calling
the equatorial sea “Occeanus” and that which includes the poles
“Amphitrites.” He believed that only one of the areas of land separated
by these seas is inhabited.[705] The same idea is reflected in words of
the _Image du monde_[706] to the effect that only a quarter of the
earth’s surface is inhabited and in the recommendation to the reader in
his imagination to cut the globe into four quarters like an apple and to
think of the habitable part as occupying the surface of one of the
quarters. Godfrey of Viterbo points out the significance of the golden
ball of empire which formed part of the regal insignia of the Holy Roman
Emperors upon which, he said, the fourfold division of the lands of the
earth’s surface was shown.[707] Among the imperial treasures
(_Reichskleinodien_) in Vienna the golden apple dating from the twelfth
century is of this form. Two bands encircling the regal ball at right
angles represent the Cratesian idea of oceans girdling the earth.[708]
In one version of the legend of St. Brandan there is a curious passage
where not only the possibility of antipodal regions is indicated but the
pious necessity of belief in such regions.[709] St. Brandan is here
reported to have read in an old book that beneath this earth there is
another world, where day prevails when it is night with us. Unable to
accept such a story, Brandan burned the book in a fit of exasperation;
and as a punishment for his incredulity God made him voyage nine years
upon the seas. What the book was we are not informed, but perhaps we do
not err in assuming that the poet had in mind a copy of the _In somnium
Scipionis commentarius_ or possibly the _De nuptiis Philologiae et
Mercurii_.
PERSISTENCE OF BELIEF THAT ANTIPODAL REGIONS WERE INHABITED
An essential feature of the theory as it had been expounded by Macrobius
and Capella, however, was the insistence that the other three temperate
areas are inhabited by races of men like our own. As belief in the
existence of inhabitants in the antipodal regions rested in our period
on the authority of Capella and Macrobius and was subjected to lively
discussion and controversy, it is not out of place for us to observe
what these two writers had actually said.
Capella, after briefly stating that three out of the five zones are
uninhabitable on account of cold and heat, declared that the other two
are tempered by a wind which encourages life.[710] The inhabitants of
the quarter south of us, beyond the equator, he called _antoikoi_; those
of the quarter also in the southern hemisphere but beyond the
north-south ocean, who have winter when we have summer, _antichthones_.
Those in our own temperate zone beyond the ocean, who have the same
summer and winter as ours but who have night when we have day, he called
_antipodes_.[711] No commerce or communication is possible between us
and these other groups of human beings, nor between one group and any of
the others. Macrobius set forth this theory in similar terms,[712]
expressly emphasizing the point that reason teaches us that the southern
zone must be inhabited because its climate is temperate like ours.
However, he added, it is not peopled by men like ourselves—Greeks,
Romans, barbarians—nor shall we ever be able to learn what sort of men
the inhabitants actually are.
Though, as we have seen, out-and-out belief in antipodeans was heretical
during the epoch we are studying, there is plenty of evidence to show
that the possibility of such a thing was an attractive subject of
speculation. The legends on the Lambert maps to which reference has been
made above would alone be sufficient to convince us of this. William of
Conches spoke very guardedly on the matter;[713] his avowed theory was
that the other temperate regions were habitable but not actually
inhabited. But are we not justified in thinking that in denying the
existence of antipodeans he was merely making a verbal concession to
theological prejudice, especially when he went on to explain that, if
there were people dwelling in other quarters, they would be called
_antoikoi_, _antipodes_, and _antichthones_, and that some would have
summer when we have winter, others night when we have day?
Gervase of Tilbury relates a fanciful story which might be interpreted
to show that he too liked to dally with the pleasing fancy that there
may be antipodeans, even though elsewhere he rejects such a possibility.
He tells of a cave in a mountain belonging to the domain of the castle
of Bech in Great Britain.[714] From this there nearly always blew a
violent wind; but once, when the wind did not happen to be blowing, a
swineherd entered the cave to look for a breeding sow which had wandered
in. Here he found an open plain with cultivated lands and harvesters
bringing in their crops, and from the harvesters he recovered his sow.
To this Gervase adds, “It was an extraordinary circumstance that wintry
coldness coming from these subterranean harvest fields seemed to
penetrate into our hemisphere, which phenomenon I think ought to be
attributed to the sun’s absence and presence elsewhere.”[715]
MANEGOLD’S ARGUMENTS AGAINST THIS DOCTRINE
The most convincing proof of the persistence in the early twelfth
century of a tendency to believe in antipodeans is furnished by the fact
that Manegold in Alsace,[716] sometime after 1103, saw fit to write a
vigorous pamphlet attacking a certain Wolfelm of Cologne, whom he
accused of harboring an heretical opinion. Manegold’s _Contra Wolfelmum
opusculum_ illustrates admirably the orthodox, or even obscurantist,
point of view. He accused Wolfelm of adhering to Macrobius’ teachings
about the four inhabited quarters of the earth. Granting that there are
four such quarters, he demanded, how can the teachings of the Holy and
Apostolic Church, buttressed by all the authority of the Fathers, the
patriarchs, and the prophets from the earliest times, be true? And how
can we believe the prophecies that the Savior will come to bring
salvation to the entire human race, if these branches of the human race
are cut off from the rest, as Macrobius would have it, by the zones and
temperatures of the earth’s surface? How could the prophecy have been
true, “All the ends of the earth will bow down before our God (_salutare
Dei nostri_), if certain ends of the earth are inhabited by men to whom
the voice of the prophets and the apostles could not reach through
impassable tracts of water, of cold, and of heat?”[717]
HABITABILITY OF THE EQUATORIAL REGION
Macrobius’ theory was also contradicted from a position opposite to that
of the orthodox churchmen. The study of Moslem astronomy brought to
Europe the opinion that the equatorial zone itself was not only
habitable but actually inhabited. In the preamble to the _Marseilles
Tables_[718] of Raymond of Marseilles, which reproduces ideas expressed
by the Spanish-Moslem astronomer Az-Zarqalī, we have an explanation of
the current theory among “philosophers” of the uninhabitability of the
polar and equatorial regions. The latter the author of the treatise
refuses to believe because the city of Arin and the temple of “Jupiter
Arenosus” are both known to lie within the equatorial zone. He proceeds
then to explain why it is physically possible for the regions beyond the
equator to be inhabited.
Peter Alphonsi,[719] also influenced by Arabic reasoning, argued that
the existence of Arin on the equator was sufficient evidence of the
habitability of the equatorial regions and gave a glowing account of the
temperate climate and attractions of those parts of the world. Man can
live throughout the entire area covered by the seven climates, he
maintained, and, as his interpretation of ancient authorities led him to
suppose that the first climate began at the equator, he was convinced
that the equator also would support human life. On the other hand, he
did not agree with the preamble to the _Marseilles Tables_, for he
maintained that the parts of the earth in the southern hemisphere beyond
Arin were not habitable. This was because the sun, on account of the
eccentricity of its orbit, approaches much nearer the earth in those
climes than it does in more northern latitudes. In this way he accounted
for the excessive cold of the Arctic and polar regions and a (supposed)
excessive heat of the trans-equatorial zones.
Plato of Tivoli’s translation of Al-Battānī’s work brought to Western
knowledge another Arabic discussion of the probable characteristics of
the areas of the earth’s surface unknown to man.[720] As to the equator,
Al-Battānī said, it was uncertain whether men had actually been there or
not. The climate, however, could not be excessively hot, because the sun
in crossing the zenith, as it does twice a year between the tropics,
does not remain directly overhead very long. Al-Battānī saw no reason
why winters and summers should not be temperate in countries along the
equator and believed that these latitudes must have, in fact, a climate
not greatly unlike that of Aden and Yemen, which, however hot it may
seem to the European, apparently did not impress the Arabs by its
torridity. The unknown districts of the world, Al-Battānī went on to
explain, comprise eleven-twelfths of the whole. Though no man had ever
reached them, he thought it not irrational to suppose that they were
like the known parts, for the sun and stars must pass across them and
produce in the same way winter and summer, the tides of the sea, and
animal and vegetable life.
GROSSETESTE ON THE HABITABLE PARTS OF THE EARTH
When we come to the close of our period, we find that Robert
Grosseteste, bishop of Lincoln, and after him his more famous pupil
Roger Bacon, like Peter Alphonsi, took over from the Moslems much
geographical and astronomical lore which they interpreted and freely
criticized.
In a book entitled _De lineis angulis et figuris_ Grosseteste elaborated
some general principles relating to the incidence and reflection of rays
from celestial bodies. The _De natura locorum_ is an attempt to show how
far these principles may be used to account for various phenomena of the
earth’s surface. Grosseteste conceived of celestial rays and influences
as emanating in an infinite number of cones, or “pyramids,” as he called
them, the apexes of which were the celestial bodies; the longer and more
oblique these pyramids, the weaker the effect of the rays upon the
earth’s surface and vice versa.[721]
Let us see how Robert applied the principle of the pyramids to explain
conditions in the equatorial zone, in the southern hemisphere, and in
the polar regions.
_The Equatorial Zone_
Logically the equatorial zone should be scorched and burnt by the sun
because the pyramids are there the shortest and the angles at which the
rays reach the earth approach nearest to a right angle. As a matter of
fact, Robert had it on the authority of Ptolemy and Avicenna that,
whereas the subtropical regions are intensely hot, the subequatorial
zone is not only temperate but extremely temperate (_temperatissimus_);
indeed, he said, theologians place Paradise under the equator in the
Orient. A modification of the principle of the pyramids was therefore
necessary. In his readiness to admit such modifications of rules that he
had laid down, Robert showed an open-minded and a scientific spirit. In
order to allow for the circumstance of a supposedly temperate equatorial
region, he stated that the heat received during the daytime must be
neutralized by the coolness of the nights, since day and night between
the tropics are always approximately the same length, as they are in the
latitudes of Europe during spring and autumn only.[722]
_The Southern Hemisphere_
The southern hemisphere, on the other hand, Robert thought to be
uninhabitable on account of the intense heat of summer and bitter cold
of winter. The excessive heat he ascribed to the fact that the
eccentricity of the solar orbit around the earth brings the sun no less
than five degrees nearer the earth during the southern summer than it
approaches during the northern summer.[723] The pyramids, or lines of
heat radiation, are therefore shorter and the heat is more intense.[724]
Conversely the southern winter must be colder than that of the north
because the sun at that season is farthest from the earth.
Granting a geocentric universe, this reasoning was sound though its
consequences were exaggerated. It is quite true that the earth is nearer
the sun in the summer of the southern than in the summer of the northern
hemisphere, yet no extreme results flow from this circumstance, and
there is no great difference in the amount of heat received by each
hemisphere.[725]
An exaggerated idea of the differences in temperatures north and south
of the equator led Robert,[726] and after him Roger Bacon,[727] to doubt
the validity of the theory of the precession of the equinoxes. This
phenomenon would inevitably produce a gradual shifting of the climatic
conditions of the southern hemisphere to the northern, and, as a result,
the latter would presumably in the course of time become uninhabitable.
Since this seemed incredible to Grosseteste and Bacon, they were
impelled to deny the possibility of its cause.
_The Polar Regions_
In discussing the climate and habitability of the polar regions,[728]
Robert cites a work, _De vegetabilibus_ (erroneously ascribed to
Aristotle in the Middle Ages) and a commentary upon it. Here the
extraordinary view was expressed that no plants or animals could survive
in the polar zone because the heat of the sun would burn them up! This
view originated in the known fact that the sun shines continuously for
half the year at the pole and at no time sinks very far below the
horizon. The commentator pointed out that the sun never retires more
than 23° out of sight and that it is capable of illuminating and heating
the atmosphere at 18° below the horizon. The theory, however, failed to
take into account the very important fact that the sun’s rays reach the
polar regions at a sharply oblique angle and that consequently their
powers of generating heat are limited. This circumstance together with
the “observations and reasoning of Aristotle, Ptolemy, and other
authorities” led the Bishop of Lincoln conclusively to reject the
singular theory of the _De vegetabilibus_ and to attribute to the polar
zones a climate that, in so far as it was dependent upon the disposition
of the heavens, rendered these regions uninhabitable on account of the
cold. Nevertheless, he recognized that there might be accidental local
conditions, such as the presence of mountains of peculiar shape, capable
in the polar regions of producing areas of intense heat or of
delightfully temperate climate. But to this subject we shall revert in a
later section devoted to the influence of mountains on climate.[729]