The ninth century was essentially a Muslim century. To be sure, intellectual work did not cease in other centuries; but the activity of the Muslim scholars and men of science was overwhelmingly superior. They were the real standard-bearers of civilization in those days. Their activity was superior in almost every respect. To consider only the first half of the century, the leading men of science, al-Kindi, the sons of Musa, Al-Khwarzmi, al-Farghani, were all Muslims; Ibn Masawaih, it is true, was a christian, but he wrote in Arabic.
Cultural Background
The seventh Abbasid caliph, al-Ma'mun (813-833), was even a greater patron of letters and science than Harun al-Rashid. He founded a scientific academy in Bagdad, tried to collect as many Greek manuscripts as possible, and ordered their translation; he encouraged scholars from all kinds, and an enormous amount of scientific work was done under his patronage.
al-Ma'mun
'Abdallah al-Ma'mun. Born in
Baghdad in 786, died near Tarsus in 833. The seventh and greatest 'Abbasid
caliph (813-833). His mother and wife were Persians, which explains his
Persian and 'Alid proclivities. He was an ardent Mu'tazil, tried to
enforce his views by means of violence. He wrote four long letters to explain
the Qur’an was created, and he cruelly punished those who dared entertain
different views (e.g., Ibn Hannibal). He thus combined in a remarkable way free
thought and intolerance. While persecuting those who objected to
Mu'tazilism, Jews and Christians were very welcome at his court. He
was even a greater patron of letters and science than Harun al-Rashid. He took
considerable pains to obtain Greek manuscripts and even sent a mission to the
Byzantine Emperor Leon the Armenian (8l3 to 890) for that purpose. He ordered
the translation of these manuscripts. He organized at Baghdad a sort of
scientific academy called the House of Wisdom (Bayt al-hilkma), which included a
library and an observatory. This was the most ambitious undertaking of its
kind since the foundation of the Alexandrian Museum (q. v. first half of third
century B. C.). He built another observatory on the plain of Tadmor (Palmyra).
The inclination of the ecliptic was found by his astronomers to equal 23o 33'
and tables of the planetary motions were constructed. He ordered two
degree-measurements to be made to determine the size of the earth one of them
near Tadmor (a degree = 6,500 miles) hence circumference of the earth = 20,400
miles; diameter=6,500 miles). A large map of the world was drawn for him.
He encouraged philosophers, philologists, traditionalists, and other jurists
mathematicians, physicians, astrologers and alchemists.
Fihrist
(116, 24.3 and passim). Gustav Weil: Gesehichte (ler Chalifen (vol.2 198-994).
J. T. Remaud: Geographie d'Aboulfeda (vol. 1, 269 sq. 1848). J. L. E. Dreyer:
History of the Planetary System from Thales to Kepler (p. 245, 249 278
Cambridge, 1906) R. A. Nicholson: Literary History of the Arabs (359
1907).
An Encyclopedic Scientist.... Al-Kindi
Abu Ysuf Ya’qub ibn Ishaq ibn al-Sabbah al-Kindi (i. e., of the tribe of
Kinda) Latin name, Alkindus. Born in Basra at the beginning of the ninth
century, flourished in Bagdad under al-Ma’ mun and al-Mu’tasim (8l3 to 849),
persecuted during the orthodox reaction led by al-Mutawakkil (841 to 861); died
c. 873. "The philosopher of the Arabs;" so-called probably because he was the
first and only great philosopher of the Arab race. His knowledge of Greek
science and philosophy was considerable.
He made a deep study of Aristotle
from Neoplatonic point of view. Relatively few of his numerous works (270?) are
extant. They deal with mathematics, astrology , physics, music, medicine,
pharmacy, and geography. He wrote four books on the use of the Hindu numerals.
Many translations from the Greek into Arabic were made or revised by him or
under his direction. He considered a1chemy as an imposture. Two of his writings
are especially important: "De aspectibus," a treatise on geometrical and
physiological optics (largely based on Euclid, Heron, Ptolemy; no dioptrics),
which influenced Roger Bacon, Witelo, etc.; "De medicinarum compositarum
gradibus," an extraordinary attempt to establish posology on a mathematical
basis. He is the earliest Muslim .writer on music whose works have come down to
us; they contain a notation for the determination of pitch. Many writings of his
were translated into Latin by Gherardo da Cremona. His influence was long
felt and Cardano considered him as one of the twelve greatest
minds.
Text and Translation - The De medicinarum compositarum
gradibus investigandis libellus was published in Strassburg (1531) Die
philosophischen Abhandlungen des al-Kindi. Zum ersten Male hrg . von Albino Nagy
(Beitr. zur Gesch. d. Philos. des Mittelalters, II, 5, 118 p., Munster,
1897.
Geometers Al-Hajjaj ibn Yusuf was the first translator of Euclid's "Elements 'into Arabic . Al-'Abbas wrote commentaries upon them . Abu Sa’id al-Darir wrote a treatise on geometrical problems. Two of the Banu Musa, Muhammad and Hasan, were especially interested in geometry; the third, Ahmad, was a student of mechanics. Books on the measurement of the sphere, the trisection of the angle, and the determination of two mean proportionals between two given quantities are ascribed to them. They discovered kinematical methods of trisecting angles and of drawing ellipses.
Arithmeticians and Algebraists The Jewish astrologer Sahl ibn Bishr wrote a treatise on algebra. The greatest mathematician of the time, and, if one takes all circumstances into account, one of the greatest of the times was al-Khwarazmi. He combined the results obtained by the Greeks and the Hindus and thus transmitted a body of arithmetical and algebraic knowledge which exerted a deep influence upon mediaeval mathematics. His works were perhaps the main channel through which the Hindu numerals became known in the west. The philosopher al-Kind1 wrote various mathematical treatises, including four books on the use of Hindu numerals. This may have been another source of Western knowledge on the subject. In any ease, the Arabic transmission eclipsed the Hindu origin, and these numerals were finally known in the West as Arabic numerals.
Translators of the "Almagest" The earliest translator of the "Almagest" into Arabic was the Jew Sahl al-Tabari. Another translation was made a little later (in 829), on the basis of a Syriae version, by al-Hajjaj ibn Yusuf.
Astronomers and Trigonometricians Ahmad al-Nahawandi made astronomical
observations at Jundishapur and compiled tables. The Caliph al-Ma’mun built an
observatory in Baghdad and another in the plain of Tadmor. His patronage
stimulated astronomical observations of every kind. Tables of planetary motions
were compiled, the obliquity of the ecliptic determined, and geodetic
measurements carefully made.
Al-Khwarizmi was one of the first to compute
astronomical and trigonometrical tables. Habash al-Hasib seems to have been one
of the greatest astronomers working for al-Ma'mun. He edited three astronomical
tables, seems to have been the first to determine the time by an altitude, and
introduced the notion of shadow (umbra versa) corresponding to our tangent.
He compiled a table of tangents, probably the earliest of its kind. Sanad
ibn 'Ali was the chief of al-Ma'mun's astronomers. Astronomical tables were
compiled by him and by Yahya ibn abi Mansur, it is probable that those tables
(and those of Habash already quoted) were due to the cooperative efforts of many
astronorners. Observations were made by the geometers al-'Abbas, 'Ali ibn 'Isa
al-Asturlabi, Yahya ibn abi Mansur, al-Marwarrudhi, and al-Khwarizmi; also the
observations made by al-Dinawari in 845-50 in Ispahan.
The geometer Abu
Sa’id al Darir wrote a treatise on the drawing of the meridian.
'Al. ibn
'Isa al-Asturlabi was a famous maker of instruments; he wrote 3 treatise on the
astrolabe. But by far the most notable of that distinguished company was
al-Fargham (Alfraganus). He was apparently the first Muslim to write a :
comprehensive treatise on astronomy. That treatise was very popular until the
fifteenth century; it influenced not only the Muslim, but also, through Latin
and Hebrew translations, the Christian and Jewish astronomers.
Astrologers It is safe to assume that every astronomer was also, incidentally an astrologer. There are a few popular men, throughout the Middle Ages, who were chiefly if not exclusively concerned with astrology, they contributed powerfully to its debasement, The main astrologers of this period were 'Umar ibn al-Farrukhan and his son Muhammad Abu Ma'shar (Albumasar), Sahl ibn Bishr, and Abu 'Ali al-Khaiyat.
Al-Hajjaj ihn Yusuf
Al-Hajjaj ihn Yusuf ibn
Matar. Flourished some time between 786 and 833. probably in Baghdad. The
first translator of Eucelid's "Elements" into Arabic and one ef the first
translators of the "Almagest." kitab al-mijisti, hence our word almagest).
Al-Hajjaj’s translation of the Almagest was made in 829-8.90 on the basis
of a Syriac version (by Sergios of Resaina'' (first half of sixth century). A
later adaptation of the Almagest was made by Abu-l-Wafa' (second half of tenth
century) .
He twice translated the "Elements'' of Euclid, first under Harun
al-Rashid then again under al-Ma'mun.
Al-'Abbas ibn Sa'id
al-'Abbas ibn Sa'id
al-Jauhari. Flourished under al-Ma mun. Muslim mathematician and astronomer. He
took part in the astronomical observations organized at Baghdad in 829.30 and at
Damaseus in 832-833. He wrote commentaries on Euclid’s Elements.
H. Suter: :Mathematiker (12, 1900)
Abu Sa’id al-Darir
Abu Sa’id al-Darir
al-Jurajani. who died in 845/6; thus he flourished in the first half of
the ninth century. Muslim astronomer and mathematician. He wrote a treatise on
geometrical problems and another on the drawing of the meridian.
H. Suter: :Mathematiker (12, 1900).
Al.-Khwarizmi
Abu 'Abdallah Muhammad ibn Musa al-Khwarizmi. The last-mentioned name (his
nisba) refers to his birthplace, Khwarizm, modern Khiva, south of the Aral Sea.
It is under that name that he was best knoxvn, as is witnessed by the words
algorism and augrim (Chaucer) derived from it. Flourished under al-Ma'mun,
caliph from 813 to 833, died c. 850. Muslim mathematician, astronomer,
geographer. One of the greatest scientists of his race and the greatest of his
time. He syneretized Greek and Hindu knowledge. He influenced mathematical
thought to a greater extent than any other mediaeval writer. His arithmetic
(lost in Arabic; Latin translation of the twelfth century extant) made known to
the Arabs and Europeans the Hindu system of numeration. His algebra, Hisab
al-jabr wal-muqabala, is equally important. It contains analytical solutions of
linear and quadratic equations and its author may be called one of the founders
of analysis or algebra as distinct from geometry. He also gives geometrical
solutions (with figures) of quadratic equations, for ex., X2 + 1OX =
39, an equation often repeated by later writers. The Liber ysagogarum
Alchorismi in artem astronomicam a magistro A. [Adelard of Bath ?] compositus!'
deals with arithmetic, geometry. music, and astronomy; it is possibly a summary
of al-Khwarzmi’s teachings rather than an original work. His astronomical
and trigonometric tables, revised by Maslama al-Majrti (Second half of tenth
century), were translated into Latin as early as l126 by Adelard of Bath. They
were the first Muslim tables and contained not simply the sine function but also
the tangent (Maslama's interpolation). Al-Khwarizmui probably collaborated in
the degree measurements ordered by al-Ma'nun. He improved Ptolemy's
geography, both the text and the maps (Surat al-ard, "The Face of the
Earth").
General Studies Fihrist (p. 274 and comm.). H. Suter:
Die Mathematiker und Astronomen der Araber (l0, 1900); Nachtrage (158-160,
1902). L. C. Karpinski's edition of the Algebra (1915.)
Sahl Al-Tabari
Also called Rabban al-Tabari, meaning the Rabbi of Tabaristan. Flourished
about the beginning of the ninth century. Jewish astronomer and physician.
The first translator of the Almagest into Arabic.
H. Suter: Die
Mathematiker und Astronomen der Araber (l0, 1900); M. Steinschneider: Die
arabische Literatur der Juden (23-34, Frankfurt, 1902).
Ahmed Al-Nahawandi
Ahmad ibn Muhammad al-Nahawandi. Flourished at Jundishapur at the time of Yahva ibn Khalid ibn Barmak, who died in 802-3; he himself died c. 835 to 845. Muslim astronomer. He made astronomical observations at Jundishapur and compiled tables called the comprehensive (Mushtamil).
H. Suter: Die Mathematiker und Astronomen der Araber (l0, 1900)
Habash Al-Hasib
Ahmad ibn 'Abdallah al-Marwazi (i. e., from Merv) Habash al-Hasib (the
calculator). Flourished in Baghdad; died a centenarian between 864 and
874. Astronomer under al-Ma'mun and al-Mu’tasim. (He observed from 825 to
835) He compiled three astronomical tables: the first were still in the Hindu
manner; the second, called the 'tested" tables, were the most important; they
are likely identical with the "Ma'munic" or "Arabic" tables and may be a
collective work of al-Ma'mun’s astronomers; the third, called tables of
the Shah, were smaller. Apropos of the solar eclipse of 829, Habash
gives us the first instance of a determination of time by an altitude (in this
case, of the sun); a method which was generally adopted by
Muslim astronomers. He seems to have introduced the notion of "shadow,"
umbra (versa), equivalent to our tangent, and he compiled a table of such shadow
which seems to be the earliest of its kind.
The astronomer Sanad ibn 'Ali is said to have made investigations on specific gravity. Al-Kindi wrote a treatise on geometrical and physiological optics; he criticized alchemy. His writings on music are the earliest of their kind extant in Arabic; they contain a notation for the determination of pitch. Among the works ascribed to the Banu Musa, is one on the balance.
Islamic Geography, and Geology
Al-Ma’mun ordered geodetic measurements, to determine the size of the earth,
and the drawing of a large map of the world. The mathematician al-Khwarizmi
wrote a geographical treatise, entitled the Face of the Earth, which was
essentially revised edition of Ptolemy's geography; it included maps.
Sulaiman the Merchant traveled to the coast-lands of the
Indian Ocean and to China; an account of his journeys was published in
851.
Some idea of Muslim views on minerals may be obtained in the so
called "Lapidary" of Aristotle. That compilation is probably of Syriac and
Persian origin, and one may tentatively place the Arabic version in the first
half of the ninth century. 'Utarid's lapidary, the earliest work of its kind in
Arabic, dates probably from the same time.
Arabic Medicine
There is nothing to report in this time on either Latin or Chinese
medicine, and that my account of Byzantine medicine is restricted to a reference
to Leon of Thessalonica. Practically all the medical work of this period was due
either to Japanese or to Arabic-speaking physicians. To consider the latter
first, I said advisedly "Arabic speaking" and not "Muslim," because out of the
eight physicians whom G. Sarton mentioned as the most important, six were
Christians, most probably Nistorians. Of the two remaining, one was a true Arab,
the other a Persian. A great part of the activity of these men was devoted to
translating Greek medical texts, especially those of Hippocrates and Galen, into
Syriac and into Arabic. All of these translators were Christians, the most
prominent being Ya'hya ibn Batriq, Ibn Sahda, Salmawaih ibn Bunan, Ibn
Masawaih, and Ayyub al-Ruhawi.
Jibril ibn Bakhtyashu'
collected Greek manuscripts and patronized the translators, but he also wrote
some medical works. Salmawaih ibn Bunan showed that the use
of aphrodisiacs, always so popular in the East, was dangerous. The greatest of
all these physicians was the Christian Ibn Masawaih (Mesue
Major). He dissected apes and composed various anatomical and medical
writings, notably the earliest ophthalmological treatise extant in Arabic
and a collection of aphorisms. The philosopher al-Kindi
wrote medical works also, the most important being one wherein he tried to
establish posology on a mathematical basis. The Persian 'Ai
al-Tabari completed, in 850, a medical encyclopaedia entitled
Paradise of Wisdom.
Ibn Sahda
Flourished at al-Karkh (a suburb of Baghdad), probably about the beginning of
the ninth century. Translator of medical works from Greek into Syriac and
Arabic. According to the Fihrist he translated some works of Hippocrates into
Arabic. According to Hunain ibn Ishaq, he translated the "De sectis" and the "De
pulsibus ad tirones" of Galen into Syriac.
Max Meyerhof:
New Light on Hunain ibn Ishaq (Isis, VIII, 704, 1926).
Jabril Ibn Bakhtyshu
Grandson of Jirjis ibn JibriI, q. v., second half of eighth century;
physician to Ja’far the Barmakide, then in 805-6 to Harun al-Rashid and later to
al-Ma'mun; died in 828-29; buried in the monastery of St. Sergios in Madain
(Ctesiphon). Christian (Nestorian) physician, who wrote various medical works
and exerted much influence upon the progress of science in Baghdad. He was the
most prominent member of the famous Bakhtyashu' family. He took pains to obtain
Greek medical manuscripts and patronized the translators.
F.
Wustenfeld: Arabische Aerzte (15-16, l840). L. Leclere: Medecine arabe (vol. 1,
99-102, 1876). M. Meyerhof: New Light on Hunain (Isls, VIII, 717, 1926).
Salmawaih Ibn Buan
Christian (Nestorian) physician, who flourished under al-Ma'mun and
al-Mu’tasim and became physician in ordinary to the latter. He died at the end
of 839 or the beginning of 840. He helped Hunain to translate Galen's Methodus
medendi and later he patronized Hunain's activity. He and Ibn Masawaih were
scientific rivals. Salmanwaih realized the perniciousness of
aphrodisiacs.
Leclerc: Medecine arabe (vol. 1, ll8,
1876). M. Meyerhof: New Light on Hunain (Isis, VIII, 71S, 1926).
Ibn Masawaih
Latin name: Mesue, or, more specifically, Mesue Major; Mesue the Elder. Abu Zakariya Yuhanna ibn Masawaih (or Msuya). Son of a pharmacist in Jundishapur; came to Baghdad and studied under Jibrll ibn Bakhtyashu'; died in Samarra in 857. Christian physician writing in Syriac and Arabic. Teacher of Hunain ibn Ishaq. His own medical writings were in Arabic, but he translated various Greek medical works into Syriac. Apes were supplied to him for dissection by the caliph al-Mu’tasim c. 836. Many anatomical and medical writings are credited to him, notably the "Disorder of the Eye" ("Daghal al-ain"), which is the earliest Systematic treatise on ophthalmology extant in Arabic and the Aphorisms, the Latin translation of which was very popular in the Middle Ages.
Text and Translation Aphorismi Johannis Damnseeni (Bologna, 1489. Translation
of the al-nawadir al-tibbiya). Many other editions. In the early editions of
this and other works, Joannes [Janus] Damascenu is named as the author.