Al-Kindi(801 — 870)

Al-Kindi

califat abbasside

6 min read

PhilosophySciencesPhilosopheMathématicien(ne)Middle AgesGolden Age of Islam, Abbasid Caliphate of Baghdad in the 9th century

Al-Kindi is regarded as the first great philosopher to write in Arabic. A polymath of the 9th century, he worked at the House of Wisdom in Baghdad and played a major role in transmitting Greek thought to the Islamic world.

Discover4 recipes

Frequently asked questions

Al-Kindi (801-870) was the first great philosopher to write in Arabic, active in Baghdad under the Abbasid caliphs. What makes him remarkable is that he managed to reconcile Greek thought (Aristotle, Plato) with Islam, without ever abandoning his faith. He worked at the House of Wisdom (Bayt al-Hikma), where he oversaw translations from Greek into Arabic. The key thing to remember is that he paved the way for falsafa (philosophy) in the Muslim world, hence his nickname.

Key Facts

  • Born around 801 in Kufa and died around 873 in Baghdad
  • Active at the House of Wisdom (Bayt al-Hikma) under the caliphs al-Ma'mun and al-Mu'tasim
  • Supervised and corrected translations of Greek works (Aristotle, the Neoplatonists) into Arabic
  • Author of more than 250 treatises spanning philosophy, mathematics, medicine, and music
  • Pioneer of cryptanalysis with his frequency analysis method for deciphering messages

Works & Achievements

Fi al-Falsafa al-Ula (On First Philosophy) (circa 830-840)

His major philosophical work, dedicated to the caliph al-Mu'tasim, which seeks to reconcile Greek philosophy with Islamic thought.

Risala fi Istikhraj al-Mu'amma (On Deciphering Encrypted Messages) (9th century)

The oldest known treatise on cryptanalysis, which describes frequency analysis of letters, the foundation of modern decoding.

De aspectibus (Treatise on Optics) (9th century)

A treatise on vision and light that influenced medieval optics in Europe after its translation into Latin.

Risala fi al-Musiqa (Treatises on Music) (9th century)

Among the first writings on music theory in Arabic, in which he studies notes, rhythms, and harmony.

On the Use of the Indian Numerals (9th century)

A work that helped spread the Indian numeral system (the “Arabic numerals”) throughout the Islamic world.

Treatises on Medicine and Pharmacology (9th century)

Writings in which Al-Kindi attempts to apply mathematics to the dosage of medicines, a pioneering approach in pharmacology.

Translation and Commentary on the Theology of Aristotle (9th century)

He supervised and corrected translations of Greek works, contributing to the introduction of Aristotle and Neoplatonism into Arabic thought.

Anecdotes

Al-Kindi worked at the "House of Wisdom

(Bayt al-Hikma) in Baghdad

where he supervised the translation of Greek works into Arabic. He was nicknamed

the philosopher of the Arabs" because he was the first Arabic-speaking thinker to embrace the legacy of Aristotle and Plato.

Al-Kindi wrote a treatise on cryptanalysis in which he describes the method of "frequency analysis

: counting how many times each letter appears in an encrypted message in order to decipher it. It is the oldest known text on this technique

the ancestor of modern decoding.

A universal mind, Al-Kindi wrote on subjects as varied as music, medicine, astronomy, optics and perfumes. He is credited with more than 260 treatises, although many have now been lost.

Under the caliph al-Mutawakkil, Al-Kindi fell out of favor: his library was confiscated and he is said to have been beaten. His rivals, jealous of his learning, helped push him out of the court.

Al-Kindi was one of the first to apply mathematics to medicine, seeking to quantify the effect of medicines. He also tried to measure the strength of remedies according to degrees, a pioneering approach for his time.

Primary Sources

On First Philosophy (Fi al-Falsafa al-Ula), dedicated to the caliph al-Mu'tasim (c. 830-840)
We should not be ashamed to acknowledge truth and to assimilate it from whatever source it comes to us, even if it is brought to us by earlier generations and foreign peoples.
Manuscript on Deciphering Cryptographic Messages (Risala fi Istikhraj al-Mu'amma) (9th century)
One way to decipher an encrypted message, if we know its language, is to find a different plaintext of the same language, long enough, and to count how many times each letter appears in it.
Biographical notice by Ibn al-Nadim, Kitab al-Fihrist (987 (10th century))
Al-Kindi was the most distinguished man of his time, unique in his knowledge of all the ancient sciences. He was called the philosopher of the Arabs.
De aspectibus (De optica), medieval Latin translation of a treatise on optics by Al-Kindi (9th century (text) / 12th century (Latin translation))
Vision occurs through the rays that issue from the eye in straight lines and fall upon the object seen.

Key Places

Kufa (Iraq)

City in Iraq where Al-Kindi was born around 801. His father was the governor there.

Basra (Iraq)

Major intellectual center where Al-Kindi received part of his early education before moving to Baghdad.

Baghdad (Iraq)

Abbasid capital where Al-Kindi worked at the House of Wisdom and spent most of his career. He died there around 870.

House of Wisdom (Bayt al-Hikma), Baghdad

A scholarly institution where Greek, Persian, and Indian texts were translated and studied. Al-Kindi played a central role there in transmitting Greek knowledge.

Samarra (Iraq)

Capital founded in 836 where Al-Kindi stayed as tutor to the son of Caliph al-Mu'tasim.

See also