As all :Mohammedan philosophy. theology, law, and statecraft is derived primarily from the Koran. its interpretation became the object of discussion at a very early period. Hence an immense literature of commentaries and super commentaries grew up. only the 111014 important of which can be mentioned: those by al-Tabari (d.923). al-Hasan al-Nisaburi (1.1015), Mo hammed al-Kurtubi (d.1272). of al-Zamaklishari (3.1t43), of Fakhr Dazi (d.1209), of al Baidawi (d.1280), andlal al-Din al-Suyuti ( d.1505 )• 110t as a system. rests as much upon the oral as upon the myritten law. The sayings and doings of Mohammed and his immediate followers form the science of the Hadith or traditions, which vary hot Ii as to value and authenticity. Around these there has also grown up a large literature; the three great col lections of such traditions were made by al-Bn khati (1.870) ,Musl hi] (S74 ) •and (S92 ) .
As early as the end of the seventh century a school of :Mohammedan jurisprudence was founded in Medina by Abd Allah ihn 31asial and Alai. Allah ibn Abbas. its decisions were col lected toward the end of the eighth century by the distinguished jurist Malik ibn Anas, whose a1-.11 a motto' became the code for the 'Hejaz. Tunis. Algeria. and Noroceo. There are three other recognized of Alm Italia:ill (q.v.). of !Mo hammed al-Shatii(3,S20). and of Altmad limn Han bal (d.855). Other (modes. to the number of seven ty-two. are prescribed as heretical. These have produced an extensive literature of elimmentaries and pandects, which has not exhausted itself in our own days.
The activity of the Mohammedans was not. con fined to philological and theological studies. With the accession of the Abbassides a new field was opened by the introduction of foreig,n civili zations. Learned men were invited from other countries and remunerated in a princely manner. The works of Greek. Syriac. Old-Persian. and Indian writers were translated into Arabic. Schools of philosophy were founded at. Bagdad. Cordova. Cairo. eta.. where the writings of Aris totle. Plato, and the Alexandrine philosophers expounded and eommtmnted 11111111. Dog mas• hitherto regarded as sacred, were freely discussed and rejected. l'TA MATES. } From these schools issued the philosophers al Kindi (eighth century). al-Farabi (900), Thu Sina (Avicenna 9S0-1037). al-Ohnzzali (1111). lim Badiali (113S), Ibn Tufail (d.1155). and Ihn 110-did( Ayerroes. 1153-9R). whose works. sub sespientlY translated into Latin. were studied for many centuries in European universities.
In mathematics the Mohammedans made great advances by introducing the numerals and other modes of notation, the sine instead of the chord, and by extending the application of al gebra. Astronomy was zealously cultivated in the schools of Bagdad, Cairo, and Cordova. Ac cording to Ibn al-Nadbi (1040), the library at Cairo possessed two ce:estial globes and six thou sand astronomical works. In the ninth century the three sons of the librarian, Musa ibn Shakr, calculated accurately the diameter of the earth and the precession of the equinoxes. At the same time lived al-Farghani, author of an astronomi cal encyclopiedia, which was translated in the twelfth century by Johannes Hispalensis. In the tenth century abBattani (Albatagnius) flourished, to whose name is attached the intro duction of trigonometrical functions, and the observation of the obliquity of the ecliptic. Among the astronomers whose works were trans lated into Latin may be mentioned Thabit ion hurrah (901), .Jabir ihn Atlah, who in 1196 con strueted the first observatory at Seville, and Nash- al-Din al-Tusi. the paraphraser of Euclid. Medicine and natural history were cultivated by the Mohammedans with a like success. In the
seventh century the writings of Galen. Hip pocrates, Paul of Aegina. etc.. were translated from the Greek into Arabic. ihn Abi Usaibiah (1203-69) devotes a whole volume to the medi cal literature in Arabic. Among the medical writers may be mentioned Mohammed al-Razi (tenth century), whose works were translated into Latin; All ibn Ridwan (1061) ; 1bn Sint (Avicenna) ; Alm al-Kasim11107). who wrote on surgery and surgical instruments; Abd Pin Zuh• (1162), and Abd Allah ihn (1248), whose Materia 3Iedica had great vogue.
History in all its forms was cultivated at an early time by the Mohammedans; several chron icles were written in the days of the Ommiad dynasty. Persian historiography influenced the Arabs to record the events of their past life as a people: and the growing interest in the prophet and his times furnished a healthy stimulus. From the middle of the eighth century we have an uninterrupted series of historians. The ear liest of these were Mohammed ihn lshak (7418), whose biography of was enlarged by 1bn Hisham (821). and Mohammed al-Wakidi (823), who wrote the• history of the prophet at Medina. No less than 140 titles of works writ ten by al-Kalbi (c.819) are mentioned. dealing largely with history and genealogy. It was a Persian, Abu Jafar (838-923). who produced the first universal history in Arabic. beginning with creation. A similar work was produced by lhn al-Athir (11130-1234). Of the early historians mention must also be made of Thu Kutaibah (892) and al-Baladhuri (8921, who deals especially with the early conquests of the Arabs. In the tenth century wrote al Hamdani (945). Hainzah al-Isfahani (0611. and el-Alasieli (956), who has left us a history of civilization. Among the historians of later een turies mention may be made of lbn Maskawai (1030). al-Makin (1273). 11)11 al-Amid (102511. al-Iliruni (13081, historian of chronology and the Herodotus of India. Alm al-Fida (1331). and lhn Khaldun (1406). the first to compose a philosophy of history. The chief historians of Spain were :Ahead al-Dhabbi 11195). ion Bash kuwal ( i S2 ) , Mohammed ibn al-Abbar (1259), and Ahead al-Makkari (1031). Among the noted historians of Egypt were Abd al-Latif (1231) and al-Makrizi (1441). More charac teristic of Arabic historiography are the numer ous local histories and biographical monographs produced. Among the most remarkable of these are the works of Jalal al-Suyuti (1505), author of 510 works, among which were histories of Cairo and Damascus; of Abu Cbaidah (824), author of 105 monographs, among which are his tories of .Mecca and Medina ; of Ali ibn Asakir (1175), author of a history of Damascus in eighty volumes, and of Balm al-Din ibn Shaddad (1234), author of a history of Aleppo. Moham med al-Shahrastani (1153) wrote a history of religious and philosophical sects which is still our chief authority on the subject. The most noteworthy biographical writers were Abe Za kariyah. al-Nawawi (1274) and Ibn Khallikan (1282), who treats of 865 persons. Bibliography was treated of by Mohammed ibn lshak al-Nadim (995), Ali ibn Yusuf al-Kifti (1248), and Hajji Khalfa (1658). With the exception of lbn Khaldun the Arabic historians lack critical sense: they are mostly mere chronographers. In geography they displayed much greater ability and have left us works of lasting value. The chief geographical writers are Ibn Hisham, dadhbah (912). Masudi. Ahmed Fadlan (921 ). Alm lshak al-Estakhri (tenth century), lbn Haukal (977). al-Slnkaddasi (985), the traveller Ibn Ilatutah (1377), Yakut (1178), who, like al-Bakri (1094). wrote an extensive geographical dictionary, al-Kazwini (1276) and Abu al-Fida.