Abu Yusuf Yaqub ibn Ishaq al-Sabbah Al-Kindi
(about 801 in Kufah, Iraq- 873 in Baghdad, Iraq)
Al-Kindi was born and brought up in Kufah, which was a centre for Arab culture and learning in the 9th century. This was certainly the right place for al-Kindi to get the best education possible at this time. Although quite a few details (and legends) of al-Kindi's life are given in various sources, these are not all consistent. Here is some details which are fairly well substantiated.
According to al'Daffa( The Muslim contribution to mathematics ,London, 1978) , al-Kindi's father was the governor of Kufah, as his grandfather had been before him. Certainly all agree that al-Kindi was descended from the Royal Kindah tribe which had originated in southernArabia. This tribe had united a number of tribes and reached a position of prominence in the 5th and 6th centuries but then lost power from the middle of the 6th century. However, descendants of the Royal Kindah continued to hold prominent court positions in Muslim times.
After beginning his education in Kufah, al-Kindi moved toBaghdad to complete his studies and there he quickly achieved fame for his scholarship. He came to the attention of the Caliph al-Ma'mun who was at that time setting up the "House of Wisdom" in Baghdad. Al-Ma'mun had won an armed struggle against his brother in 813 and became Caliph in that year. He ruled his empire, first from Merv then, after 818, he ruled from Baghdad where he had to go to put down an attempted coup.
Al-Ma'mun was a patron of learning and founded an academy called the House of Wisdom where Greek philosophical and scientific works were translated. Al-Kindi was appointed by al-Ma'mun to the House of Wisdom together withal-Khwarizmi
and theBanu Musa brothers
. The main task that al-Kindi and his colleagues undertook in the House of Wisdom involved the translation of Greek scientific manuscripts. Al-Ma'mun had built up a library of manuscripts, the first major library to be set up since that at Alexandria, collecting important works from Byzantium. In addition to the House of Wisdom, al-Ma'mun set up observatories in which Muslim astronomers could build on the knowledge acquired by earlier peoples.
In 833 al-Ma'mun died and was succeeded by al-Mu'tasim. Al-Kindi continued to be in favour and al-Mu'tasim employed al-Kindi to tutor his son Ahmad. Al-Mu'tasim died in 842 and was succeeded by al-Wathiq who, in turn, was succeeded as Caliph in 847 by al-Mutawakkil. Under both these Caliphs al-Kindi fared less well. It is not entirely clear whether this was because of his religious views or because of internal arguments and rivalry between the scholars in the House of Wisdom. Certainly al-Mutawakkil persecuted all non-orthodox and non-Muslim groups while he had synagogues and churches in Baghdad destroyed. However, al-Kindi's [ E Craig (ed.), Routledge Encyclopedia of Philosophy 5 (London-New York, 1998), 250-252] ... lack of interest in religious argument can be seen in the topics on which he wrote. ... he appears to coexist with the world view of orthodox Islam.
In fact,most of al-Kindi's philosophical writings seem designed to show that he believed that the pursuit of philosophy is compatible with orthodox Islam. This would seem to indicate that it is more probably that al-Kindi became [Biography in Dictionary of Scientific Biography (New York 1970-1990)]:... the victim of such rivals as the mathematiciansBanu Musa
and the astrologer Abu Ma'shar.
It is claimed that theBanu Musa brothers
caused al-Kindi to lose favour with al-Mutawakkil to the extent that he had him beaten and gave al-Kindi's library to theBanu Musa brothers
Al-Kindi was best known as a philosopher but he was also a mathematician and scientist of importance [A A al'Daffa, The Muslim contribution to mathematics (London, 1978) ]:To his people he became known as ... the philosopher of the Arabs. He was the only notable philosopher of pure Arabian blood and the first one in Islam. Al-Kindi "was the most leaned of his age, unique among his contemporaries in the knowledge of the totality of ancient scientists, embracing logic, philosophy, geometry, mathematics, music and astrology.
Perhaps, rather surprisingly for a man of such learning whose was employed to translate Greek texts, al-Kindi does not appear to have been fluent enough in Greek to do the translation himself. Rather he polished the translations made by others and wrote commentaries on many Greek works. Clearly he was most influenced most strongly by the writings ofAristotle
but the influence ofPlato
can also be seen in al-Kindi's ideas. We should certainly not give the impression that al-Kindi merely borrowed from these earlier writer, for he built their ideas into an overall scheme which was certainly his own invention.
Al-Kindi wrote many works on arithmetic which included manuscripts on 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 on space and time, both of which he believed were finite, 'proving' his assertion with a paradox of the infinite. Garro gives al-Kindi's 'proof' that the existence of an actual infinite body or magnitude leads to a contradiction in [I Garro, al-Kindi and mathematical logic, Internat. Logic Rev. No.
(1978), 145-149]. In his more recent paper , Garro formulates the informal axiomatics of al-Kindi's paradox of the infinite in modern terms and discusses the paradox both from a mathematical and philosophical point of view.
In geometry al-Kindi wrote, among other works, on the theory of parallels. He gave a lemma investigating the possibility of exhibiting pairs of lines in the plane which are simultaneously non-parallel and non-intersecting. Also related to geometry was the two works he wrote on optics, although he followed the usual practice of the time and confused the theory of light and the theory of vision.
Perhaps al-Kindi's own words give the best indication of what he attempted to do in all his work. In the introduction to one of his books he wrote (see for example:Biography in Dictionary of Scientific Biography ,New York 1970-1990):It is good ... that we endeavor in this book, as is our habit in all subjects, to recall that concerning which the Ancients have said everything in the past, that is the easiest and shortest to adopt for those who follow them, and to go further in those areas where they have not said everything ...
Certainly al-Kindi tried hard to follow this path. For example in his work on optics he is critical of a Greek description byAnthemius
of how a mirror was used to set a ship on fire during a battle. Al-Kindi adopts a more scientific approach (see for example: Biography in Dictionary of Scientific Biography ,New York 1970-1990):
Anthemius should not have accepted information without proof ... He tells us how to construct a mirror from which twenty-four rays are reflected on a single point, without showing how to establish the point where the rays unite at a given distance from the middle of the mirror's surface. We, on the other hand, have described this with as much evidence as our ability permits, furnishing what was missing, for he has not mentioned a definite distance.
Much of al-Kindi's work remains to be studied closely or has only recently been subjected to scholarly research. For example al-Kindi's commentary onArchimedes
' The measurement of the circle has only received careful attention as recently as the 1993 publication  by Rashed.
J J O'Connor and E F Robertson
Here is a list of his works:
1. al-Kindi (before 873) Rasa’il al-Kindi al-falsafiya (Philosophical Treatises of al-Kindi), ed. M.A. Abu Ridah, 2 vols in 1, Cairo, 1953. (The standard collection of al-Kindi’s treatises, with introductory notes in Arabic.
2. al-Kindi (before 873) Fi al-falsafa al-ula (On First Philosophy), ed. and trans. A. L. Ivry, Al-Kindi’s Metaphysics: A translation of Ya‘qub ibn Ishaq al-Kindi’s Treatise ‘On First Philosophy’, Albany, NY: State University of New York Press, 1974. (A clear account of al-Kindi’s metaphysics with English translation.)
3. al-Kindi (before 873) Risalah fi al-hilah li-daf‘ al-ahzan (On the Art of Averting Sorrows), ed. and trans. H. Ritter and R. Walzer, ‘Uno scritto morale inedito di al-Kindi’, Memorie della Reale Accademia nazionale dei Lincei, Rome, Series VI, 8 (1), 1938, 47–62. (Text and Italian translation.)
4. al-Kindi (before 873) Fi hudud al-ashya’ wa-rusumiha (On the Definitions of Things and their Descriptions), ed. M. A. Abu Ridah in Rasa’il al-Kindi al-falsafiya,Cairo, 1953; trans. D. Gimaret in Cinq épîtres,Paris: Centre National de la Recherche Scientifique, 1976. (Al-Kindi’s treatise on definitions.)
5. al-Kindi (before 873) Fi wahdaniya allah wa tunahiy jirm al-‘alam (On the Unity of God and the Limitation of the Body of the World), ed. M. A. Abu Ridah in Rasa’il al-Kindi al-falsafiya,Cairo, 1953. (Al-Kindi on the nature of God.)
6. al-Kindi (before 873) Fi kammiya kutub Aristutalis wa ma yahtaj ilahi fi tahsil al-falsafa (The Quantity of the Books of Aristotle and What is Required for the Acquisition of Philosophy), ed. M. A. Abu Ridah in Rasa’il al-Kindi al-falsafiya, Cairo, 1953. (Writings on Aristotle.)
Some references and further readings:
1. Gimaret, D. (1976) Cinq epitre , Paris: Centre National de la Recherche Scientifique. (An excellent French translation with commentary of five treatises by al-Kindi. There are unfortunately very few English translations of al-Kindi’s works.)
2. Jadaane, F. (1968) L’Influence du stoïcisme sur la pensée musulmane (The Influence of Stoicism on Muslim Thought), Beirut: Dar el-Machreq. (An interesting argument for Stoic, rather than merely Aristotelian and Neoplatonic influence, on the Islamic philosophers.)
3. Jolivet, J. (1971) L’Intellect selon Kindi, Leiden: Brill. (A classic work: extensive commentary and French translation of al-Kindi’s treatise on the intellect.)
4. Klein-Franke, F. (1996) ‘Al-Kindi’, in S. H. Nasr and O. Leaman (eds) History of Islamic Philosophy, London: Routledge, ch. 11, 165–77. (Account of the role of al-Kindi as the first Muslim philosopher, and in particular the links between his philosophy and contemporary theology and understanding of Greek thought.)
5. Moosa, M. (1967) ‘Al-Kindi’s Role in the Transmission of Greek Knowledge to the Arabs’, Journal of the Pakistan Historical Society 15 (1): 3–18. (Good discussion of ‘The Quantity of the Books of Aristotle’.)
6. Rosenthal, F. (1940) Review article of ‘Uno scritto morale’, Orientalia IX: 182–91. (An interesting review of the Ritter–Walzer treatise, still important despite its age.)
7. Stern, S. M. (1959) ‘Notes on al-Kindi’s Treatise on Definitions’, Journal of the Royal Asiatic Society parts 1 and 2: 32–43. (Considered a classic.)
Taken from: http://www-history.mcs.st-andrews.ac.uk/history/References/Al-Kindi.html