Ya’qub b. Ishaq al-Kindi, shortly al-Kindi, also known as „the philosopher of the Arabs“, was an Iraqi philosopher, mathematician, astronomer, physician and many other things (he started small revolutions in chemistry, medicine, and music too).
Al-Kindi was born in Kufa (about 800 CE), present day Iraq, about 170 km south of Baghdad and 10 km northeast of Najaf. At the time, Kufa was a cultural center, creating the right atmosphere for, among other things, making of the Kufic script – the earliest alphabet of the Arabic language. It was a very stimulating environment for a young scientist willing to question things and search for new methods and new ideas.
On the scientific front, Al-Kindi plays a central role in Islamic scholarship for two principal reasons: his early role in establishing a scientific methodology and the diversity of subjects he addressed. In his work, al-Kindi was mainly interested in philosophical thought from Greece, as well as a multitude of disciplines such as medicinal treatments, astrology, mathematics, the making of steel weapons, and others.
According to Ibn al-Nadim, al-Kindi wrote at least two hundred and sixty books, contributing heavily to geometry, medicine, philosophy, logic, and physics (still, like so many other scholars of Islamic tradition, al-Kindi remains understudied – less than forty of his works are extant and even those have not been completely edited and studied).
His greatest contribution to the development of Islamic philosophy was his efforts to make Greek thought both accessible and acceptable to a Muslim audience. He was also the first philosopher writing in the Arabic language. A recurring theme in al-Kindi’s works was his belief that orthodox Islam is not in conflict with philosophy as a whole. He did produce many arguments in favor of the congruent relationship that can exist between philosophy and Islam. However, this earned al-Kindi some enemies in the learned societies, the Banu Musa brothers and the astrologer Abu Ma’shar in particular. Al-Kindi stayed true to his views on life:
“Our residence in this phenomenal world is transitory; it is a journey towards the eternal one. The most miserable man, is he who prefers for himself the material above the spiritual, for the material, apart from its ephemeral nature, obstructs our passage to the spiritual world. Man should not `disregard any means to protect himself against all human vices, and he should seek to rise to the highest ends of human virtues…, that is, to the knowledge by means of which we protect ourselves against spiritual and bodily disease, and acquire the human virtues in whose very essence goodness is grounded.“
Rasa’il al-Kindi al-falsafiya, i. 280; in G.N. Atiyeh, Al-Kindi
Al-Kindi authored works on a number of important mathematical subjects, including arithmetic, geometry, the Indian numbers, the harmony of numbers, lines and multiplication with numbers, relative quantities, measuring proportion and time, and numerical procedures and cancellation. He also wrote four volumes, On the Use of the Indian Numerals (Ketab fi Isti’mal al-‘Adad al-Hindi) which contributed greatly to diffusion of the Indian system of numeration in the Middle-East and the West.
Talking about physics and geometry, al-Kindi was successful in formulating the theory of parallels. He looked into the prospect of having pairs of straight lines in a plane which are non-parallel and non-intersecting at the same time. He wrote several manuscripts with his findings on the subject, which he later compiled into books.
His most significant gift to the development of medicine was his systematic classification of the dosage to be given to patients. In one of his books, he presented precisely the correct dose for each medication used at the time, which helped standardize the preparation of recipes.
Always remaining curious about the world around him, al-Kindi produced many miscellaneous manuscripts on different subjects ranging from his views on alchemy and precious stones to the astronomical path that the planets follow. Much of this hard work is now lost in history. We know of it only through referring sources, many of them in Latin, who hint at al-Kindi’s breakthrough findings, inventions, and observations.
There is anecdote which might decribe al-Kindi’s character the best.
Once the grandson of a governor of al-Kufah asked him:
“How is it that you are never seen asking at the door of the sultan, or at the gatherings of businessmen?”
“These are places where the likes of you seek their fortunes, I seek mine there where nobody ever dreams of taking it away from me.“
(Quoted by G.N. Atiyeh in Al-Kindi)
For more on al-Kindi’s life and his work, go to Alshindagah, Muslim Heritage, and on cis-ca.org you can find a comprehensive list of the titles he wrote. Also, there are some of his books avilable on Oxford University Press.