CHAPTER LV_A History of Magic and Experimental Science, Volume 2 (of 2) During the First Thirteen Centuries of Our Era

ROBERT GROSSETESTE

Chief sources for Robert Grosseteste--Reasons for Roger

Bacon’s eulogy--Grosseteste’s scholarly career--His

writings: absence of magic--His scientific writings

little affected by his ecclesiastical position--Reliance

on experience--Theory of vision and science of

perspective--Experimental discovery of lenses--Mentioned

also in _The Romance of the Rose_--Theories formed

by experimenters with lenses--Mathematical physics:

the radiation of virtue--The _Computus_ and calendar

reform--Juggling with numbers--From mathematics to

astronomy to astrology--Astrology in natural philosophy,

agriculture, alchemy, medicine and music--Some astrological

technical detail--Man and the stars--Grosseteste’s theory

of comets--Alchemy--Other treatises--_Summa philosophiae_

ascribed to Grosseteste--Its contents--Oriental origin

of philosophy--Greek men of learning--Arabs and medieval

Christians--Ancient and modern science compared--Criticism

of Aristotle and the Arabic text--Use of the word

“modern”--Theology, philosophy, and science; speculative and

experimental--Astrology in the _Summa_--Occult virtue and

alchemy--Brother Giles on the comet of 1264--Appendix I. The

Perspective or Optics of Witelo.

[Sidenote: Chief sources for Robert Grosseteste.]

The fame of Robert Grosseteste,[1421] who lived from about 1175 to 1253

and was bishop of Lincoln during the last eighteen years of his life,

rests largely upon the praises of his countrymen and contemporaries,

Matthew Paris and Roger Bacon, and upon his own writings. The

historian, Matthew Paris, depicts him especially as the man of affairs,

the churchman and statesman who dared oppose either king or pope for

England’s sake. But with his repeated resistance in parliament to

royal financial exactions, his outspokenness against abuses at the

papal court and his refusal to admit papal provisors to benefices in

his diocese, his aggressive and reforming activity in his bishopric

and consequent quarrels with the monastic orders and his own cathedral

chapter--with all this side of his career we are little concerned. It

is rather as a great scholar of his time that like Roger Bacon we shall

look back upon him.

[Sidenote: Reasons for Roger Bacon’s eulogy.]

Bacon’s eulogies of Grosseteste may seem rather extravagant. Writing

fourteen years after his death he thinks that no living scholar can

compare with him, nay, he ranks him and Adam Marsh, another Englishman

of whom we know little, as in their day what Solomon, Aristotle and

Avicenna were in theirs.[1422] One reason for this high praise is

presumably that Grosseteste had been Bacon’s favorite teacher, and

certainly that he was interested in the same learned pursuits, Greek

and Hebrew, mathematics, optics, experimental science, as the friar

who followed him. Roger practically admits that he owes much in those

fields to Robert and an examination of Grosseteste’s writings makes

this fact still more evident.

[Sidenote: Grosseteste’s scholarly career.]

A letter by Giraldus Cambrensis written before the close of the twelfth

century speaks of the then youthful Grosseteste as already proficient

in law and medicine. He seems to have been born of humble and poor

parents at Stradbrook in Suffolk.[1423] He was educated at Oxford where

he became _rector scholarum_ and Chancellor and in 1224 the first

rector of the Franciscans at Oxford. He perhaps also studied at Paris.

After holding various archdeaconries and other prebends he was elected

bishop of Lincoln in 1235 but continued his interest in the welfare of

the university at Oxford. Roger Bacon, in affirming that Grosseteste

surpassed all others in knowledge of the sciences, gives as a reason

his long life and experience as well as his enthusiasm for study;[1424]

and in another passage declares that hitherto it has taken thirty or

forty years for a man to become really proficient in mathematics, as

the case of Robert Grosseteste among others shows.[1425] Bacon also

states that it was not “until the latter portion of his life” that he

undertook the work of making translations and summoned Greeks and had

grammars brought from Greece and other lands. Since Grosseteste appears

at first to have studied law and medicine rather than ancient languages

and mathematical sciences, Bacon’s statements suggest that the works of

Grosseteste which we are about to consider were written late in life.

This inference is further borne out by a passage in the treatise _De

impressionibus aeris seu de prognosticatione_ which gives the positions

of the seven planets in the signs of the zodiac and states the date as

“the Arabic year 646 or the year of grace 1249.”[1426]

[Sidenote: His writings: absence of magic.]

Our discussion of Grosseteste will be based upon some treatises

included in Baur’s edition of his philosophical works. They are mostly

brief and in some cases seem rather fragmentary. We shall not be

concerned with his Greek grammar or with his theological writings,

which occupy half of the bibliography in Pegge’s Life.[1427] His

letters contain some hints of his scientific works but nothing bearing

on magic or astrology. It used to be stated that Grosseteste certainly

constructed charms to expel maladies, that he invented forms of words

to exorcise fiends, and that he worked cures by engraved gems.[1428]

The ascription to Grosseteste of treatises on Necromancy and Sorcery,

and the Philosopher’s Stone, is, however, false and grew, Baur says,

from marginal glosses appended to one of his genuine works.[1429] What

we shall note in Grosseteste’s works will be mainly his attitude to

experimental science on the one hand and to astrology on the other.

[Sidenote: Scientific writings little affected by his ecclesiastical

position.]

In these scientific treatises by Grosseteste there is little to suggest

the Christian bishop. However, in the work “On the Fixity of Motion and

Time” he opposes the Aristotelian doctrine that the universe or motion

of the celestial bodies is eternal.[1430] And in a second treatise, “On

the Order of the Emanation of Things Caused from God,” he expresses the

wish that men would cease to question the scriptural account of the age

and beginning of the world.[1431] A third treatise “On Freedom of the

Will” also lies on the frontier of philosophy and theology.

[Sidenote: Reliance on experience.]

Grosseteste affords us further examples in a number of passages of

that reliance upon experience and reason, that rejection of certain

views as contrary to experience, and yet that acceptance of statements

in old authors as based upon experience, which we saw in Galen and

William of Auvergne’s “experimental books,” and shall see in Albertus

Magnus and the other medieval scientists. Grosseteste speaks, however,

not merely of experience or _experimenta_, but also of experimenters

(_experimentatores_).[1432] We may first note some use of observation

and experience in astronomy and geography. In his treatise on comets

he alludes to “experience in natural things.”[1433] In his treatise

on the Sphere[1434] Bishop Robert declares that the sphericity of

the earth and of all the stars and planets “is shown both by natural

reasons and astronomical experiences,” that is, in the case of the

earth, by the observations of the sky by men in different parts of

the earth. In the same work he says that Thabit ben Corra (836-901

A. D.) working over the operations of Ptolemy, “found by certain

experiments that the motion of the fixed stars was different.”[1435]

Likewise in his treatise _On the Generation of the Stars_ Grosseteste

remarks of one contention that “experience shows the contrary” and of

another view that it “is against both experience and reason.”[1436]

Again in writing _Of the Nature of Places_ he adduces in support of

his positions “experiments and reasons,” and “divers authors and

experimenters.”[1437] The old legend of the Hyperboreans who dwell

among mountains near the pole in such a salubrious and temperate

climate that they live on and on until they tire of life and commit

voluntary suicide by leaping off cliffs into the sea, Grosseteste

introduces by the statement: “It has also been found by experience, as

authors tell”--among whom he names Pliny, Solinus, and “Marcianus in

his geometry.”

[Sidenote: Theory of vision and science of perspective.]

In the realm of physics Grosseteste not only mentions experience in

discussing vision and what he calls Perspective but also brings to

our notice a recent or approaching experimental discovery, that of

magnifying lenses. In his treatise on the rainbow he makes a rather

unpromising beginning. After arguing whether the sense of sight

operates by the eye receiving something within itself, as natural

philosophers are prone to hold, or by sending forth a visual species

or rays, he decides as was usual with men of his time in favor of

the latter alternative.[1438] He cites Aristotle in his last book on

animals as saying that a man with deep-set eyes sees farther because

his visual virtue is not spread or scattered but goes straight--as if

from a long-barreled gun--to the things seen.

[Sidenote: Experimental discovery of lenses.]

Grosseteste then goes on to say that there are three parts of

Perspective. The first is that concerning the sight with which he has

just been dealing. The second concerns mirrors. The third has been

“untouched and unknown among us until the present time. Yet we know

that Aristotle completed this third part”--he of course did nothing

of the sort--“and that it is much more difficult in its subtlety and

far more wonderful in its profound knowledge of natures than the

other parts. For this branch of Perspective thoroughly known shows us

how to make things very far off seem very close at hand and how to

make large objects which are near seem tiny and how to make distant

objects appear as large as we choose, so that it is possible for us

to read the smallest letters at an incredible distance, or to count

sand or grain or grass or any other minute objects.”[1439] So far the

passage reads as if it might be merely the exaggerated dream of fancy.

But Grosseteste proceeds to state “how these marvels happen,” which

seems to be by the breaking up of “the visual ray”--or as we should

say, by the refraction of rays of light--as it passes through several

transparent objects or lenses of varying nature. He explains also that

great distance does not make an object invisible but the narrowness of

the angle under which it is seen.[1440] This he proceeds to illustrate

“by experiments” (_per experimenta_). Again in his treatise on comets

he mentions “those who have experienced that by a transparent figure

interposed between the spectator and the object seen it is possible

that the thing seen should be multiplied and that great things seem

small and conversely according to the shape given the interposed

transparent object.”[1441] I have given as far as possible a literal

translation of Grosseteste’s words on this point in order to convey his

exact or inexact meaning. If these passages are not a sufficient proof

that magnifying lenses of some sort were already discovered, they at

least point the way to the microscope and telescope, and we know that

eye-glasses for nearsightedness were in use at the latest by the end

of the thirteenth century.

[Sidenote: Mentioned also in _The Romance of the Rose_.]

Very similar and perhaps copied from this very treatise of Grosseteste

on the rainbow--or from its source (Al-Hazen)--are some verses in the

continuation of the French _Romance of the Rose_ written by Jean de

Meun, probably about 1270. Besides remarking of rainbows that--the

words are Ellis’ translation--[1442]

“Only he who’s learned the rule

Of optics in some famous school

Can to his fellow men explain

How ’tis that from the sun they gain

Their glorious hues;”

the poet mentions burning-glasses and various types of mirrors, and

also tells us that from optics one

“... may learn the cause

Why mirrors, through some subtle laws

Have power to objects seen therein--

Atoms minute or letters thin--

To give appearance of fair size,

Though naked unassisted eyes

Can scarce perceive them. Grains of sand

Seem stones when through these glasses scanned.”

The poet adds that by these glasses one can read letters from such a

distance that one would not believe it unless he had seen it. Then he

concludes:

“But to these matters blind affiance

No man need give; they’re proved by science.”

[Sidenote: Theories formed by experimenters with lenses.]

Returning to Grosseteste and experimental method we may note his

mention in the same treatise upon comets of “those who reflect and

experiment in natural phenomena and form their opinions from their

experiments without foundation of reasons.”[1443] Grosseteste holds

that such experimenters “necessarily fall into false notions concerning

the natures of comets,” because they try to explain them as reflected

rays and the like after the analogy “of their varied experiments which

they have employed in radiations and the producing of fires”--probably

by burning glasses--“and by what is seen through the medium of lenses”

(_diaphanorum_). The important point for us, however, is not whether

these men were wrong about comets, but their varied experimentation and

their basing of hypothesis upon their experiments.

[Sidenote: Mathematical physics: the radiation of virtue.]

In view of Grosseteste’s interest in physical and astronomical matters,

and his training, if we believe Bacon, for some thirty or forty years

in mathematics, it is not surprising that he realized something of the

value of mathematics in the study of natural science. He believed that

a knowledge of geometry was of great aid to the “diligent investigator

of natural phenomena” in explaining the causes of all natural effects.

In a treatise “On lines, angles and figures,” or “On refraction and

reflexion of rays,” Grosseteste holds that not only vision or light

but every natural agent sends forth its virtue to the object affected

and acts upon sense or matter along geometrical lines.[1444] This

doctrine of radiation or emanation of force seems to date back at

least to Plotinus, and we have heard Alkindi among the Arabs in his

treatise on Stellar Rays say that the stars and all objects in the

world of the four elements emit rays of this sort. From any given agent

virtue radiates forth in all directions, but a perpendicular line is

the shortest and strongest line of force between it and any other

single point or object. From a point or center of influence to a larger

surface we get pyramids or cones of radiated force. The same theory is

set forth by Roger Bacon under the name “multiplication of species”

but even this wording is not new with him, since Grosseteste speaks of

the natural agent as “multiplying its virtue” from itself to the thing

affected, and then explains that this virtue is also sometimes called

“species” and sometimes “similitude” and is the same in whatever way

it is named.

[Sidenote: The _Computus_ and calendar reform.]

The _Computus_, or treatise on reckoning time and keeping track of

Easter especially and also other church festivals, had been a variety

of mathematical and astronomical exercise indulged in by the clergy

even in the darkest periods of the early middle ages. The _Computus_ of

Grosseteste pointed out the need of reforming the Julian calendar then

in use, and he also called attention to this need in his treatise on

_The Sphere_. From the later use made of it by Roger Bacon[1445] and by

Cardinal Pierre d’Ailly[1446] in the early fifteenth century one infers

that Grosseteste’s _Computus_ remained an authoritative work upon the

subject of calendar reform.[1447]

[Sidenote: Juggling with numbers.]

On one occasion at least Grosseteste’s interest in mathematics

degenerated into one of those puerile reveries on the relations

and perfection of certain numbers in which so many authors since

Pythagoras, if not before him, had indulged. Having stated that in “the

supreme body” there are four things, namely, form, matter, composition

and compound, Grosseteste states that form is represented by the

number one, matter by two, and composition by three, “since there is

patent in it formed matter and materialized form and the property of

composition itself.”[1448] The compound besides these three things has

its own nature and so is represented by four. Now 1 + 2 + 3 + 4 = 10.

“Wherefore every whole and perfect thing is ten.”

[Sidenote: From mathematics to astronomy to astrology.]

That Grosseteste’s “mathematics” includes astronomy is indicated by

his citing “_mathematicos_” as explaining that the sun burns the

regions under the tropic of capricorn more than those under the tropic

of cancer, because an eccentric of the sun when it is in capricorn

brings it closer to the earth.[1449] These mathematicians disagree on

this point with the commentator upon Aristotle who believed that the

sun burned more in Cancer. If for Grosseteste mathematics included

astronomy, astronomy also included astrology--although he does not

usually employ the word _mathematicus_ for an astrologer. To his

attitude toward astrology we now turn.

[Sidenote: Astrology in natural philosophy, agriculture, alchemy,

medicine and music.]

Grosseteste accepts astronomy or astrology as the supreme science

and says in his treatise on the liberal arts that natural philosophy

needs its aid more than that of the others.[1450] There is scarcely

any operation whether of nature or of man, such as the planting of

vegetables, or transmutation of minerals, or cure of diseases, which

can dispense with astronomical assistance. For inferior nature does

not act except as celestial virtue moves and directs it. He then goes

on to detail the effects of the moon, Saturn, and Mars on the hour

of planting, and then to emphasize the importance of selecting the

favorable hours astrologically in medical practice and in alchemy where

he associates the seven planets with seven metals.[1451] He also argues

that the harmony of the movements of the celestial spheres is found

also in their effects upon the inferior world.[1452] Therefore he who

knows the due proportion of the elements in the human body and the

concord of the soul with the body, can restore any lack of harmony in

the same to its proper state.[1453] In other words, diseases and even

wounds and deafness should be curable by music based upon a knowledge

of astrology and mathematics, and one should also be able to control

such emotions as joy, grief, and wrath.

[Sidenote: Some astrological technical detail.]

In another treatise on how to predict the weather (_De impressionibus

aeris seu de prognosticatione_[1454]) Grosseteste says that one must

know such things as the powers of the signs and the natures of the

planets.[1455] He then relates the four elements and four qualities

to the planets and signs and proceeds to such further technical

astrological terms as house, exaltation, _triplicitas_, _terminus_,

_facies_, and aspect, and to an explanation of the effect of the

eccentrics of the sun and moon upon inferior objects.[1456]

[Sidenote: Man and the stars.]

Grosseteste, like most of our Christian authors, exempts man in part

by virtue of his free will and rational soul from the control of the

stars. One of his brief fragments is entitled “That man is a microcosm”

(_Quod homo sit minor mundus_), that is, a replica of the surrounding

universe.[1457] One of his arguments for the finiteness of this world

and of the stars is that all things are made for man and that when he

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 more.[1458] In a treatise on freedom of the

will, he follows Augustine in _The City of God_ in affirming that the

rational soul is sublimer than the stars and in denying that all our

actions which seem to be freely willed by us are predictable from the

constellations, and that fate prevails as a necessity in all inferiors

from the motion of the stars. He admits, however, that the human body

is subject to two forces; as part of the world of cause it is changed

in many ways by the movements of the stars, but it also is subject to

the control of the mind especially in voluntary actions.

[Sidenote: Grosseteste’s theory of comets.]

Grosseteste has an ingenious theory which I do not remember having met

elsewhere to explain why comets are signs of great disasters. In his

treatise on comets he states that a comet is sublimated fire which has

been separated from terrestrial nature and assimilated to celestial

nature.[1459] The cause of this separation and assimilation by which

comets are generated is the virtue of the heavenly bodies. Moreover,

each comet has a particular star of its own which draws it as iron is

drawn by adamant. This star, even if it is one of the fixed stars, must

be related to one of the planets and hence the comet is under some

planet also. Grosseteste then further explains that in every earthly

object there are incorporated through the action of the celestial

bodies particles of a more spiritual sort assimilated to the celestial

natures. The generation of a comet, a process in which these fiery or

ethereal particles are released from matter and carried up on high,

is therefore the first step and sign of a more general release of the

spiritual nature and of the consequent corruption of the terrestrial

objects and compounds concerned, namely: in the first place, those

under the rule of the same planet as the comet in question, and,

in the second place, those in the region from which the comet was

sublimated.[1460] But it is not easy to discern over which region the

comet has especial significance of all those regions which are under

the same parallel in which it appears, unless, concludes Grosseteste

naïvely, it is that region where men are most alarmed by it.

[Sidenote: Alchemy.]

Grosseteste makes one or two incidental allusions to alchemy which

show that he was a believer in the possibility of transmuting metals.

He avers that nature intended that all metals should be gold, and that

they vary from it only by degrees of imperfection.[1461] In another

passage[1462] he mentions a theory of “the doctors of alchemy” that

in each natural object there is, besides the four elements composing

it, a fifth essence, unchangeable in itself but alterable after it has

descended into inferior bodies. Here again we find a connection between

alchemy and astrology.

[Sidenote: Other treatises.]

It is probable that not all of Grosseteste’s astrological writings are

included in Baur’s edition. He mentions but does not publish a Digby

manuscript and another of the thirteenth century in the Bibliothèque

Nationale. Both are astronomical or astrological.[1463] A fourteenth

century manuscript in the British Museum contains a treatise of

“Grosthede” on the medicinal virtues of herbs.[1464] After the name of

each herb the word “Grosthede” is usually added as if the items were

extracts from a larger work. The treatise is not included in Baur’s

edition and is perhaps spurious.

[Sidenote: _Summa philosophiae_ ascribed to Grosseteste.]

Baur includes in his edition of Grosseteste’s philosophical works

a _Summa philosophiae_ which is longer than the other scientific

treatises put together but which is probably spurious. The latest

authors whom it cites are Alexander of Hales who died before

Grosseteste and Albertus Magnus who possibly had written many of his

works and made his reputation before 1253 although he lived on until

1280. Its several mentions of Albert are much more likely, however,

to have been penned by some younger man than Grosseteste.[1465] And

unless a passage referring to the death of Simon de Montfort after the

appearance of a comet in 1264[1466] is an interpolation, the _Summa_

cannot be by Grosseteste, unless in the sense that it represents his

teaching or is an incomplete work of his to which someone else later

put the finishing touches.

[Sidenote: Its contents.]

The _Summa_ is, like the encyclopedias of Bartholomew of England and

Thomas of Cantimpré, in nineteen books,[1467] a number perhaps chosen

in deference to the seven planets and twelve signs of the zodiac. These

books are devoted to the following topics: 1. the rise of philosophy;

2. truth; 3. science; 4. matter; 5. form; 6. virtue; 7. the first

cause; 8. the universe--one but not eternal; 9. bodies, space, and

vacuum; 10. intelligence and intelligences; 11. the rational soul;

12. the sensitive soul; 13. the vegetative soul; 14. light; 15. the

sphere or heavens; 16. nature, universal and particular, and natural

virtue; 17. elements and compounds; 18. meteorology; 19. minerals and

metals.[1468]

[Sidenote: Oriental origin of philosophy.]

The account of the rise of philosophy includes considerable mention

of occult sciences, with which it would seem to have been closely

associated from the first.[1469] The Chaldeans are called the first

famous philosophers. Sem is regarded as the founder of astrology and

Cham, whom some identify with Zoroaster, is said to have invented the

seven liberal arts. Abraham’s instruction of the Egyptians in astrology

and arithmetic is next mentioned and then Atlas and his nephew Mercury,

and the latter’s grandson Trismegistus, of the same name, are spoken

of. This second Mercurius Trismegistus was according to Albumasar an

illustrious astrologer, pre-eminent in theology and alchemy and magic

and a famous prophet, but according to Augustine he was very worthless

(_vanissimus_) in many respects. Long after this Homer revealed

philosophy in his stories and Solomon philosophized concerning the

nature of vegetables and animals, but in parables, it is believed.

[Sidenote: Greek men of learning.]

After mention of Abrachys, the astrologer of King Nebuchadnezzar,

the author then lists the Greek philosophers from Thales to

Socrates.[1470] The first philosopher in Italy was Pythagoras who

had been thoroughly instructed in the science of the stars and magic

by the Persians, Chaldeans and Egyptians. In less than a page a good

estimate and contrast of Plato and Aristotle is made,[1471] and the

author tries to explain why until the time of Arabic culture Plato

was almost universally preferred to Aristotle among the Greeks and

Latins. There follows a list of the learned Greeks: Empedocles,

Heraclitus, Hippocrates, Euclid, Archimedes, and various orators,

astronomers, astrologers, and naturalists (_naturales_) concluding with

“Callisthenes the famous alchemist.”[1472]

[Sidenote: Arabs and medieval Christians.]

Among the Arabs three groups are distinguished of philosophers,

_mathematici_ or astrologers--among whom we are amazed to find Julius

Firmicus listed, and medical writers.[1473] Thebit also is classed with

the Arabs, but Plato of Tivoli, Costa ben Luca, Algazel, Gundissalinus,

Constantinus, Theophilus Macer, and Philaretus are distinguished as

Christian, and both Rabbi Moses as Hebrews.

[Sidenote: Ancient and modern science compared.]

Approaching his own time the author says that there are many other

men whose excellent works of philosophy he has inspected but of whose

names he is ignorant or has his reasons for keeping silent about.[1474]

He does, however, name John the Peripatetic and Alfred, and still

more recently Alexander the Minorite and Albert of Cologne, the

friar preacher, as eminent philosophers and yet not to be considered

authorities. The author nevertheless has no uncritical veneration for

the learned men of the past. He thinks that with the exception of the

Peripatetics very few of them had a complete or correct knowledge of

the principles of nature and causes of natural phenomena or concerning

the transmutation of the elements and the composition of physical

bodies.[1475] Compared with moderns he finds their comprehension

slight, except as they had fewer problems to occupy them and got

results by concentrating for a long time on these. But he can think of

no one among them except Boethius who was not guilty of some erroneous

opinion. This attitude, however, is perhaps more owing to Christian

prejudice than scientific superiority on our author’s part.

[Sidenote: Criticism of Aristotle and the Arabic text.]

Even Aristotle does not escape criticism. We are told that we should

not accept his statement concerning the number of movers of the

heavenly spheres, for, as Avicenna and Rabbi Moses have pointed out,

the science of astronomy was little developed in his time.[1476] Nor

are the Arabian commentators upon Aristotle left uncensured. It is said

that some of the works of Aristotle in their present form smack more

of Arabic loquacity than of Greek eloquence or the Aristotelian style,

and that, especially in the Arabic text, interpolations and additions

and alterations have been made involving patent anachronisms. Probably

there have also been corresponding omissions.[1477] These criticisms of

the Arabic text of Aristotle remind us of those which Roger Bacon said

Grosseteste made.

[Sidenote: Use of the word “modern.”]

The author of this _Summa_ is quite fond of employing the word “modern”

which we heard him use above. He also tells how “Ptolemy, and other

more modern _mathematici_” introduce epicycles in the orbits of the

planets to save appearances, but have not fully determined “whether

it is really so.”[1478] He also speaks of “Avenalpetras and the more

modern Arabs” and calls Albertus Magnus “the most famous of the more

modern theologians.”[1479]

[Sidenote: Theology, philosophy, and science; speculative and

experimental.]

It is rather outside the limits of our investigation, but I cannot

refrain from noting the _Summa’s_ division of theologians into three

classes: first, those who are original and have been made saints by

the pope; second, those who are original and have not been sainted;

third, the unoriginal minds who compile _Summae_ from the works of

the other two classes.[1480] The author believes that theology may

utilize philosophy to refute heretics but that it must beware of making

philosophy its chief end and should use theological terms as far as

it can.[1481] Later he states that there are eight celestial spheres,

according to the philosophers, nine according to the theologians who

include the waters above the firmament as one.[1482] The author divides

science into theoretical or speculative and practical or operative.

He also has a touch of experimental science, asserting that very many

experiences have proved that water will harden into stone,[1483] that

the rules of genethlialogy and the predictions of astrologers are based

upon the many specific cases observed and classified from experience

by past astrologers,[1484] that many experiences in his own age--some

of which he presently mentions--have shown that terrible events always

follow the appearance of a comet,[1485] and that the alchemists had

learned from many experiments that metals can be transmuted.

[Sidenote: Astrology.]

This favoring attitude toward astrology and alchemy is about all that

there is left for us to notice in the _Summa_. The author thinks

that no one has ever adequately treated the virtues appropriate to

each planet, but quotes Rabbi Moses and Albumasar somewhat on this

point.[1486] He has no difficulty in believing simultaneously in

freedom of the will and genethlialogy.[1487] He also cites the passage

in Albumasar concerning the astrological prediction of the virgin birth

of Jesus Christ.[1488] In discussing comets, instead of attempting

to explain their signifying disaster to whole regions naturally, as

we heard Grosseteste do in his treatise on comets, the author of the

_Summa_ holds that “they appear of necessity by the will of God alone,

not by chance or nature, but by the ministry of intelligences.”[1489]

This was also the case with the star seen at Christ’s nativity. It

may be, however, that this entire passage about comets and other

astrological matters is an interpolation in the _Summa_, since it is in

it that the mention of the date 1264 occurs to which we before alluded.

The writer then goes on to say that his master, who was “most skilled

in natural and mathematical science and most perfect in theology and

most holy in life and religion,” taught him that Noah’s flood was

necessitated by a constellation which God had foreordained for the

wickedness of the then world.[1490] This, too, is perhaps a sign of an

addition by some disciple of Grosseteste.

[Sidenote: Occult virtue and alchemy.]

The author of the _Summa_ believes in occult virtue in nature and

attributes it to the stars.[1491] He accepts Albertus Magnus’s

explanation of the marvelous virtues of gems as due to celestial

influence.[1492] He believes that metals are generated in the earth by

the same force and are seven in number according to the seven planets,

and thinks that this process can be simulated by alchemy.[1493] In

discussing that subject Hermes is his chief authority. The _Summa_

terminates by explaining the superiority of steel to iron and listing

various salts.[1494]

[Sidenote: Brother Giles on the comet of 1264.]

Since we have mentioned the comet of 1264, we may note farther that

it was the occasion of a treatise by Brother Giles of the Order of

Dominicans, on the essence, motion, and signification of comets,[1495]

in which he cites Grosseteste _De iudiciis_ and alludes to the death of

Pope Urban IV in that year. The comet was seen in the kingdom of France

from mid-July to October and “stupefied the minds of many.”

FOOTNOTES:

[1421] References to Grosseteste’s works, unless otherwise stated, will

be to Ludwig Baur, _Die Philosophischen Werke des Robert Grosseteste_,

Münster, 1912, in Baeumker’s _Beiträge zur Geschichte der Philosophie

des Mittelalters_, Vol. IX. This edition seems to make little effort to

correct errors of case or number in the MSS, so that much of the text

is far from being smooth reading. Baur discussed _Die Philosophie des

Robert Grosseteste_ in Vol. XVIII (1917) of the same series. The life

of Grosseteste is treated briefly in DNB, and more fully in the old

and pedantic work of Samuel Pegge, _The Life of Robert Grosseteste_,

London, 1793, 385 quarto pages with many foot-notes and appendices,

which however are based mainly on the works of preceding antiquaries,

the author stating in his preface, “my private station as a country

clergyman would not permit me to have much access to public libraries,

but the materials were chiefly to be sought for in a book-room which,

you will easily suppose, cannot be very richly or amply furnished.”

Pegge’s Life was already described in 1861 as “one of the scarcest

of modern works”; but the British Museum possesses two copies. Other

biographies are by J. Felten, Freiburg, 1887, and F. Stevenson, London,

1889. The letters of Grosseteste, which do not especially concern us,

are edited by H. R. Luard in RS XXV, 1861.

Not to be confused with Grosseteste is Robertus Anglicus who wrote

a commentary on the _Sphere_ of Sacrobosco in 1271, a _Tractatus

quadrantis_ at Montpellier in 1276 (printed 1508), and _Canons for the

Astrolabe_ (printed at Colle about 1478): see Duhem, III (1915), pp.

292, 298.

[1422] Brewer, 70 and 75.

[1423] Pegge (1793), p. 8, and Appendix II.

[1424] Brewer, 91; Bridges, I. 67.

[1425] Brewer, 472.

[1426] Baur, 49-50. If, on the other hand, the mention of an Arabic

year indicates that the treatise is a translation of an Arabic work,

the date would seem almost too late for Grosseteste to have effected

the translation. It will be recalled that Bartholomew of England

included “Robert of Lincoln” in his bibliography.

[1427] Pegge (1793), 267-91.

[1428] Wharton, _Anglia Sacra_, II, 325-41, _de vita Grosteste auctore

Richardo monacho Bordenienso_. This life was apparently written about

1500.

[1429] Baur, 124.

[1430] Baur, 105.

[1431] Baur, 150.

[1432] Baur, 68.

[1433] Baur, 36.

[1434] In _Sacro Bosco, Joannes de, Sphera, cum commentis_, 1518,

_Reverendissimi Episcopi Roberti Lincolinensis Sphere Compendium_, fol.

131 (B1). Baur, 13. _De sphaera_.

[1435] Baur, 25, _De sphaera_; _Sacro Bosco_, fol. 133 (F2).

[1436] _De generatione stellarum_, Baur, 33 and 34.

[1437] _De natura locorum_, Baur, 68.

[1438] _De iride, seu de iride et speculo_, Baur, 72-73.

[1439] Baur, 74.

[1440] Baur, 75.

[1441] Baur, 41.

[1442] In the Temple classics, vol. III, pp. 113-4.

[1443] Baur, 40.

[1444] Baur, 60.

[1445] See below, chapter 61, p. 644.

[1446] See the frequent citations of Grosseteste in his _De Correctione

Kalendarii_, in an edition of the works of d’Ailly and Gerson printed

about 1480.

[1447] On the general subject, Kaltenbrunner, _Die Vorgeschichte der

gregorianischen Kalendarreform_, 1876.

[1448] _De luce seu de inchoatione formarum_, Baur, 58.

[1449] _De natura locorum_, Baur, 69.

[1450] _De artibus liberalibus_, Baur, 5.

[1451] Baur, 6-7.

[1452] Baur, 3.

[1453] Baur, 4-5.

[1454] Dover Priory, 409, fol. 80r, _Pronostica Roberti Grosteste_,

would seem from its opening words, “_Hoc ornamentum_ ...” to be the

geomancy ascribed to various authors rather than this treatise by

Grosseteste.

[1455] Baur, 42.

[1456] Baur, 44.

[1457] Baur, 59.

[1458] Baur, 106.

[1459] Baur, 38.

[1460] Baur, 39-40.

[1461] _De artibus liberalibus_, Baur, 6.

[1462] _De generatione stellarum_, Baur, 36.

[1463] Baur, 143.

[1464] Sloane 3468, fols. 43v-64r.

[1465] Baur, 280, 505, 633.

[1466] Following the passage in question, 587-88, other events

mentioned are in the life of Emperor Frederick II and Louis IX’s

departure from Aigues-Mortes to Egypt in 1248.

[1467] In _Erh Ya_, the earliest Chinese dictionary, the entries are

arranged for ready reference under nineteen heads.

[1468] These headings are not given in the text but are made up by me

to indicate its contents.

[1469] I, 1, (Baur, 275-77). For the origins of “mathematical science”