Tag Archives: Medieval

Jew of the Week: Avraham bar Chiya haNasi

The Rabbi Who Discovered the Quadratic Formula

Avraham bar Chiya (c. 1070-1145) was born in Barcelona to a Sephardic Jewish family. It appears that his family was persecuted by its Christian rulers, so they fled to the neighbouring Arab kingdom of Zaragoza. Bar Chiya came from a long line of rabbis, and was also extensively trained in science, math, and astronomy. Famed for his wisdom, he became the court astronomer of Al-Musta’in II. Eventually, he was appointed minister of police and given the title sahib al-shurtah, “city governor”. This is why he was known in the Jewish community as HaNasi, “the prince” or “the president”. Al-Musta’in II was unable to defend his domain from the Christians, who soon took over. Bar Chiya moved to southern France for a while and lived in Narbonne and Provence. There he composed some of the most important scientific texts of the Medieval era. He translated a number of Arabic works into Latin, opening their study for Europeans, and played a key role in introducing the Hindu numerals we use today (by way of Arabia) to Europe, and thus to the rest of the world. Bar Chiya also synthesized ancient Greek wisdom with contemporary Arabic knowledge, and published new discoveries in number theory, arithmetic, geometry, optics, astronomy, and music theory. His Treatise on Measurement and Calculation inspired later greats like Plato of Tivoli and the world-famous Fibonacci. Meanwhile, Bar Chiya also served as the chief rabbi of the Jewish communities he presided over, and composed two important Jewish commentaries and texts. He is credited with being the first person to write a scientific book in Hebrew, and played an instrumental role in the development of the Hebrew language. His disciples included both Jews and non-Jews, among them the great Rabbi Abraham ibn Ezra, and the Flemish astronomer Rudolf of Bruges. The first historical appearance of the quadratic equation (with a complete solution of x2 – ax + b = c) appears in one of Bar Chiya’s works! He is also referenced in many philosophical works as “Abraham Judaeus”. All in all, his impact on the development of science, mathematics, and human history is unparalleled.

Jew of the Week Turns 10 Years Old Today!

What I Learned from 10 Years of Writing Jew of the Week

Words of the Week

The mind of man plans his way, but God directs his steps.
King Solomon (Proverbs 16:9)

Jew of the Week: Moses Maimonides

Maimonides

Moshe ben Maimon (1135-1204), known in the Jewish world as the Rambam (his initials) and to the rest of the world as Moses Maimonides, was born in Cordoba, Spain, the son of a famed rabbi. In 1148, the Almohads conquered Cordoba and began persecuting the Jews. Maimonides’ family fled and remained on the move across Spain for 10 years before settling in Morocco. There, Maimonides studied at the University of al-Karaouine, focusing on the field of medicine. At the same time, he composed his famous commentary on the Mishnah – the central text of Jewish oral laws. Along with his two sons, he then traveled to the Holy Land, despite the danger of the ongoing Crusades. After visiting the holy sites and praying at the Temple Mount, he journeyed to Egypt and settled there, continuing his work and studies at the local yeshiva. During this time, he played a central role in saving a community of Jews taken captive by King Amalric I. In 1171, Maimonides was appointed president of the Egyptian Jewish community. When his brother’s merchant ship sank in the Indian Ocean, Maimonides lost all of his wealth and started working as a physician. Having studied both Greek and Arabic medicine, and being well-versed in folk healing and mysticism, Maimonides quickly became the top doctor in the world and was soon hired by the legendary Sultan Saladin. Even after Saladin’s death, Maimonides remained the royal family’s physician, and rejected offers by a handful of European kings. He wrote a number of healing manuals that were influential for many future generations (and still studied today). He also composed several religious and philosophical works, including the famous Guide for the Perplexed and Treatise on Logic. His Mishneh Torah remains one of the central compilations of Jewish law to this day. He also set forth Judaism’s 13 Principles of Faith. Scholars are puzzled at how he was able to accomplish so much: his typical day included a visit to the Sultan’s Palace before returning home to a long line of patients that lasted into the night. He would rarely take any breaks, and ended his day hungry and spent. Even on Shabbat he had little rest, dealing with life-or-death situations that trumped the sanctity of observing the Sabbath. Many believe that he passed away because of this difficult lifestyle. Maimonides writes that he wished he had more time to pray, study, and grow closer to God, but his obligation to care for the masses superseded all these. He passed away on December 12th (809 years tomorrow) to great sorrow, and true to his nature, had demanded the humblest of funerals. He remains highly respected in Spain and across the Middle East, the Arab world (as Abu Musa bin Maymun) and the medical community. Countless institutions continue to bear his name, and he is a central hero for modern Jews as a man who was both pious and worldly, bridging the gaps between Torah and science, Jewish wisdom and secular philosophy.

 

Words of the Week

Gems from Moses Maimonides:

“Do not consider it proof just because it is written in books, for a liar who will deceive with his tongue will not hesitate to do the same with his pen.”

“Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.”

“No disease that can be treated by diet should be treated with any other means.”

“One who wishes to attain human perfection must therefore first study Logic, next the various branches of Mathematics in their proper order, then Physics, and lastly Metaphysics.”

“One should see the world, and see himself as a scale with an equal balance of good and evil. When he does one good deed the scale is tipped to the good – he and the world is saved. When he does one evil deed the scale is tipped to the bad – he and the world is destroyed.”

Jews of the Week: Khazars

The Medieval World’s Greatest Kingdom

Map of Khazaria – The Medieval Jewish Kingdom

The Khazars (c. 650-1016 CE) A perplexing people with unknown origins who rose to European and Asian dominance, the Khazars are most famous for their national conversion to Judaism. Speculated to have begun as a Turkic break-away kingdom, the Khazars spread quickly to encompass the entire Caucasus region, southern Russia and parts of Eastern Europe. In the 700s, the Khazars waged a series of wars against the superpower Arab Caliphate, which historians agree prevented Europe from becoming an Islamic continent. Around 740 CE, King Bulan, feeling a lack of spirituality in his warrior life, invited representatives of the major religions. He found truth in Judaism and converted. Keeping with the Jewish way, he did not impose his new lifestyle on anyone. Nonetheless, the nobility slowly followed suit and by 860 CE, so had most of the kingdom. The Khazars dominated world trade, controlling much of the Silk Road. The silver coins that they minted (called Yarmaqs) are commonly found in places like China and England, and in 1999 a large reserve of these coins was found in Sweden, bearing the inscription “Moses is the Prophet of God”. Sadly, the kingdom declined after a series of revolts, was then overrun by the Rus, and destroyed by the Mongols.

Words of the Week

Stay away – to the ultimate degree – from “holy wars.” Not because we lack the means of prevailing or because of timorousness, but because we must consecrate all our strength exclusively to strengthening our own structure, the edifice of Torah and mitzvot performed in holiness and purity
Rabbi Sholom DovBer of Lubavitch