YAQUB IBN ISHAQ AL-KINDI
Abu Yousuf Yaqub Ibn Ishaq al-Kindi was born at Kufa around 800 C.E. His
father was an official of Haroon al-Rashid. Al-Kindi was a contemporary of
al-Mamun, al-Mu'tasim and al-Mutawakkil and flourished largely at Baghdad. He
vas formally employed by Mutawakkil as a calligrapher. On account of his
philosophical views, Mutawakkil was annoyed with him and confiscated all his
books. These were, however, returned later on. He died in 873 C.E. during the
reign of al-M'utamid.
Al-Kindi was a philosopher, mathematician, physicist, astronomer,
physician, geographer and even an expert in music. It is surprising that he made
original contributions to all of these fields. On account of his work he became
known as the philosopher of the Arabs.
In mathematics, he wrote four books on the number system and laid the
foundation of a large part of modern arithmetic. No doubt the Arabic system of
numerals was largely developed by al-Khawarizmi, but
al-Kindi also made rich contributions to it. He also contributed to spherical
geometry to assist him in astronomical studies.
In chemistry, he opposed the idea that base metals can be converted to
precious metals. In contrast to prevailing alchemical views, he was emphatic
that chemical reactions cannot bring about the transformation of elements. In
physics, he made rich contributions to geometrical optics and wrote a book on
it. This book later on provided guidance and inspiration to such eminent
scientists as Roger Bacon.
In medicine, his chief contribution comprises the fact that he was the first
to systematically determine the doses to be administered of all the drugs
known at his time. This resolved the conflicting views prevailing among
physicians on the dosage that caused difficulties in writing recipes.
Very little was known on the scientific aspects of music in his time. He
pointed out that the various notes that combine to produce harmony, have a
specific pitch each. Thus, notes with too low or too high a pitch are non-pleasant. The degree of harmony depends on the frequency of notes, etc. He
also pointed out the fact that when a sound is produced, it generates waves in
the air which strike the ear-drum. His work contains a notation on the
determination of pitch.
He was a prolific writer: the total number of books written by him was 241,
the prominent among which were divided as follows:
Astronomy 16, Arithmetic 11, Geometry 32, Medicine 22,
Philosophy 22, Logic 9, Psychology 5, ar,d Music 7.
In addition, various monographs written by him concern tides, astronomical
instruments, rocks, precious stones, etc. He was also an early translator of
Greek works into Arabic, but this fact has largely been over-shadowed by his
numerous original writings. It is unfortunate that most of his books are no
longer extant, but those existing speak very high of his standard of scholarship
and contribution. He was known as Alkindus in Latin and a large number of his
books were translated into Latin by Gherard of Cremona. His books that were
translated into Latin during the Middle Ages comprise Risalah dar Tanjim,
Ikhtiyarat al-Ayyam, Ilahyat-e-Aristu, al-Mosiqa,
Mad-o-Jazr, and Aduiyah Murakkaba.
Al-Kindi's influence on development of science and philosophy was significant
in the revival of sciences in that period. In the Middle Ages, Cardano
considered him as one of the twelve greatest minds. His works, in fact, lead to
further development of various subjects for centuries, notably physics,
mathematics, medicine and music.