Al-Samawʾal ibn Yaḥyā al-Maghribī (, c. 1130 – c. 1180), commonly known as Samawʾal al-Maghribi, was a

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

and

physician A physician, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the Medical education, study, Med ...

. Born to a Jewish family of

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

n origin, he concealed his

conversion to Islam Reversion to Islam, also known within Islam as reversion, is adopting Islam as a religion or faith. Conversion requires a formal statement of the '' shahādah'', the credo of Islam, whereby the prospective convert must state that "there is none w ...

for many years for fear of offending his father, then openly embraced Islam in 1163 after he had a dream telling him to do so. His father was a

rabbi A rabbi (; ) is a spiritual leader or religious teacher in Judaism. One becomes a rabbi by being ordained by another rabbi—known as ''semikha''—following a course of study of Jewish history and texts such as the Talmud. The basic form of t ...

from

named Yehuda ibn Abūn.

Mathematics

Al-Samaw'al wrote the mathematical treatise ''al-Bahir fi'l-jabr'', meaning "The brilliant in algebra", at the age of nineteen. He also used the two basic concepts of

mathematical induction Mathematical induction is a method for mathematical proof, proving that a statement P(n) is true for every natural number n, that is, that the infinitely many cases P(0), P(1), P(2), P(3), \dots all hold. This is done by first proving a ...

, though without stating them explicitly. He used this to extend results for the

binomial theorem In elementary algebra, the binomial theorem (or binomial expansion) describes the algebraic expansion of powers of a binomial. According to the theorem, the power expands into a polynomial with terms of the form , where the exponents and a ...

up to n=12 and

Pascal's triangle In mathematics, Pascal's triangle is an infinite triangular array of the binomial coefficients which play a crucial role in probability theory, combinatorics, and algebra. In much of the Western world, it is named after the French mathematician Bla ...

previously given by

al-Karaji (; c. 953 – c. 1029) was a 10th-century Persian mathematician and engineer who flourished at Baghdad. He was born in Karaj, a city near Tehran. His three principal surviving works are mathematical: ''Al-Badi' fi'l-hisab'' (''Wonderful on ...

Polemics

He also wrote a famous

polemic Polemic ( , ) is contentious rhetoric intended to support a specific position by forthright claims and to undermine the opposing position. The practice of such argumentation is called polemics, which are seen in arguments on controversial to ...

book in

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

debating

Judaism Judaism () is an Abrahamic religions, Abrahamic, Monotheism, monotheistic, ethnic religion that comprises the collective spiritual, cultural, and legal traditions of the Jews, Jewish people. Religious Jews regard Judaism as their means of o ...

known as ''Ifḥām al-Yahūd'' (''Confutation of the Jews''). A

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

tract translated from Arabic and later translated into many

Western Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US *Western Creek, Tasmania, a locality in Australia *Western Junction, Tasmania, a locality in Australia *Western world, countries that id ...

languages, titled ''Epistola Samuelis Marrocani ad R. Isaacum contra errores Judaeorum'', claims to be authored by a certain R. Samuel of Fez "about the year 1072" and is erroneously connected with him.Samau'al al-Maghribi: Ifham Al-Yahud: Silencing the Jews by Moshe Perlmann, Proceedings of the American Academy for Jewish Research, Vol. 32, Samau'al Al-Maghribi Ifham Al-Yahud: Silencing the Jews (1964)

Notes

References

* * * Samau'al al-Maghribi: Ifham Al-Yahud: Silencing the Jews by Moshe Perlmann, Proceedings of the American Academy for Jewish Research, Vol. 32, Samau'al Al-Maghribi Ifham Al-Yahud: Silencing the Jews (1964) *Samaw'al al-Maghribi: Ifham al-yahud, The early recension, by مغربي، السموءل بن يحي، d. ca. 1174. al-Samawʼal ibn Yaḥyá Maghribī; Ibrahim Marazka; Reza Pourjavady;

Sabine Schmidtke Sabine Schmidtke is a German academic, historian, and scholar of Islamic studies. She is Professor of Islamic Intellectual History at the Institute for Advanced Study in Princeton. Schmidtke was elected Member to the American Philosophical So ...

Publisher: Wiesbaden : Harrassowitz, 2006. *Perlmann, Moshe, "Eleventh-Century Andalusian Authors on the Jews of Granada" Proceedings of the American Academy for Jewish Research 18 (1948–49):269-90.

External links

Al-Bahir en Algebre d'As-Samaw'al translation by Salah Ahmad, Roshdi Rashed, Author(s) of Review: David A. King, Isis, Vol. 67, No. 2 (Jun., 1976), pp. 307-308
*Al-Asturlabi and as-Samaw'al on Scientific Progress, Osiris, Vol. 9, 1950 (1950), by Franz Rosenthal, pp. 555–566 *
PDF version
{{DEFAULTSORT:Samawal, Yahya Maghribi Astronomers of the medieval Islamic world Physicians of the medieval Islamic world Medieval Jewish astronomers 12th-century mathematicians Mathematicians of the medieval Islamic world Converts to Islam from Judaism People from Baghdad Year of birth uncertain Medieval Iranian Jews 12th-century physicians Medieval Jewish physicians Jews from the Abbasid Caliphate 12th-century births 12th-century deaths 12th-century astronomers Iraqi people of Moroccan descent 12th-century people from the Abbasid Caliphate Jewish astronomers 12th-century Jews from the Abbasid Caliphate