Islamic leaders, their biographies and accomplishments. Saul Silas Fathi

and sophisticated mathematical equations in their research laboratories in Baghdad, Damascus, Cairo and Merv, the Europeans were struggling to perform simple mathematical calculations using Roman numerals. By contrast, the introduction of Arabic numerals represented nothing short of a major revolution in mathematical study and research. No other mathematician played a more pivotal role in the development of algebra and Arabic numerals that al-Khwarizmi. That is why he is today considered to be one of the greatest mathematical geniuses of all time.

      Abu Abdullah Muhammad ibn Musa al-Khwarizmi was born in Khwarizm, in the Central Asian province of Khurasan. Al-Khwarizmi’s family migrated to the district of Qurtrubulli, located on the outskirts of Baghdad, when he was still a child. The students who were considered to be most capable and gifted by their tutors were then encouraged to pursue research in medicine, astronomy, alchemy and mathematics, thereby widening their intellectual horizons.

      When al-Khwarizmi’s reputation as an accomplished religious scholar, scientist and mathematician reached the corridors of power in Baghdad, the reigning Abbasid Caliph, Abdullah al-Ma’mun, invited him to join his celebrated bait al-Hikmah (The House of Wisdom) in Baghdad around 820; he was around forty at the time. Originally founded by Harun during his reign as Caliph, the bait al-Hikmah became one of the Muslim world’s most famous and influential libraries and centers of research under Caliph al-Ma’mun’s patronage. As expected, al-Khwarizmi occupied a prominent position in bait al-Hikmah, where he studied and conducted research in a host of disciplines including astronomy, geography, history, music and mathematics, which was his favorite subject. He authored an influential book on history entitled Kitab al-Tarikh (The Book of History), which later inspired celebrated Muslim historians like Abul Hasan al-Mas’udi and al-Tabari to produce their own works on the subject.

      The Muslim scientists and mathematicians not only translated and preserved ancient Greek intellectual heritage (such as Euclid’s Elements, Ptolemy’s Almagest and the vast corpus of Aristotelian logic for the benefit of posterity), they also explored and analyzed the intellectual and cultural contribution of other ancient civilizations, including those of Persia, India and China. According to some historians, al-Khwarizmi’s quest for knowledge took him all the way to India, where he mastered traditional Indian science and mathematics. It was also during his stay in India that he became familiar with the zero-based decimal system for the first time. During this period al-Khwarizmi discovered that the ancient Indians used a blank space to denote ‘nothing’ or ‘nil’ (Sunya), which inspired him to coin the Arabic word sifr meaning ‘nothing’, just as its Latin equivalent, ciphrium, later came to denote ‘zero’. His discovery of the concept of ‘zero’ enabled him to lay the foundations of a new decimal system, which is today widely known as Arabic numerals, and in so doing he revolutionized the study of mathematics forever.

      Al-Khwarizmi’s complete mastery of Greek, Indian and Babylonian mathematics enabled him to critically evaluate the contribution of the ancients before he went on to develop his own fresh ideas and thoughts on the subject. The originality of his mathematical contribution is most evident from the fact that the word ‘algebra’ was derived directly from the title of his famous book on the subject, entitled Kitab al-Mukhtasar fi Hisab al-Jabr wa’l Muqabalah (The Summarized Treatise on the Process of Calculation for Transposition and Cancellation). He used around eight hundred different demonstrative equations to show how calculations of integration and equation could be performed.

      Al-Khwarizmi’s book on arithmetic entitled Kitab al-Jam’ wa’l Tafriq bi’l Hisab al-Hindi (The Book of Aggregation and Division in Indian Mathematics) was not only a pioneering mathematical contribution, it also be came a hugely influential book. After Bon Compagni translated it into Latin in 1157, it became a popular textbook on arithmetic throughout medieval Europe. Al-Khwarizmi’s scholarship had such a pervasive influence on Western science and technology that he became known as ‘Algorithm’ across Europe, and throughout the centuries his Latinized name became synonymous with the word ‘arithmetic’ in the West. Without al-Khwarizmi’s seminal contributions in arithmetic, algebra, trigonometry and other branches of mathematics, it would not have been possible for Copernicus, Kepler, Galileo, Newton and others to achieve as much as they did in the fields of astronomy, physics, mathematics and chemistry.

      Al-Khwarizmi was also a brilliant astronomer and geographer. He not only accurately measured and determined the sphericity of the earth, he also suggested ways in which the process could be made easier in the future, by improving the device he had invented. Towards the end of his life he authored a book on geography entitled Kitab Surat al-Ard (The Book on the Shape of the Earth). In this book, he went to great lengths to correct Ptolemy’s misconceptions about different aspects of geography, geology and other related sciences.

      In total, al-Khwarizmi authored more than a dozen books on all the sciences of his time. He died at the age of sixty-seven and was laid to rest in Baghdad.

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Al-Kindi (801-873): Rescued from being a footnote in history by the Prophet Muhammad, the Arabs embraced learning, culture and civilization like never before. It was al-Kindi, that hugely influential Islamic philosopher – known in the West as the ‘philosopher of the Arabs’ (faylasuf al-Arab) - who played a central role in the development of philosophical thought in the Muslim world.

      Abu Yusuf Yaqub ibn Ishaw al-Kindi, known in the Latin West as Alkindus, was born in the Iraqi city of Kufah. Along with Basrah, Baghdad, Damascus, Makkah and Madinah, Kufah was one of the foremost centers of Islamic learning at the time.

      After completing his formal education in Kufah, al-Kindi moved to Baghdad, the political capital of the Islamic world, to pursue advanced training in the religious and philosophical sciences. After the death of Harun al-Rashid in 809, his son al-Ma’mun – having defeated al-Amin – became the Caliph and vigorously promoted the study of the rational sciences, including Greek philosophy and science, across the Muslim world. In Baghdad, al-Kindi enjoyed the patronage of Caliph al-Ma’mun who encouraged him to pursue his studies at the bait al-Hikmah (House of Wisdom), the celebrated library and research center originally founded by Harun al-Rashid. At the bait al-Hikmah, al-Kindi devoted all his time and energy to the study of mathematics, astronomy, chemistry, musical theory and philosophy.

      Along with other luminaries of the time, including al-Khwarizmi the great mathematician and scientist, and al-Farghani the renowned astronomer, al-Kindi became a prominent member of bait al-Hikmah. Given al-Kindi’s intellectual brilliance and great linguistic abilities, Caliph al-Ma’mun became very fond of him and asked him to spearhead the pioneering task of translating Greek, Persian and Indian philosophical, mathematical and scientific works into Arabic for the benefit of the Muslim scholars and researchers. Thanks to al-Kindi and his colleagues, the study of comparative thought became one of the foremost intellectual preoccupations of the early Muslim philosophers and scientists.

      Al-Kindi was appointed chief astrologer at the Caliphal court in Baghdad when he was only thirty-two years old. However, it was in the fields of optics, music and philosophy that he made some of his most original contributions. For the first time in the history of optics, al-Kindi fully explained the principle of rectilinear progress of light emerging from a luminous object. Using a lit candle, hence becoming known as the ‘candle experiment’, al-Kindi was able to demonstrate that light progressed in a straight line. His contribution in the field of musical theory was equally remarkable. Since musical songs formed an important part of Arab culture, he was keen to develop a theoretical understanding of music – a branch of learning which the Muslims later exported to the West.

      Though al-Kindi’s contributions in optics and musical theory were nothing short of remarkable, today he is most famous for his philosophical originality and writings. The author of twenty-two books on philosophy, he became a towering figure in this subject both in the Muslim world and in the West, where he became widely known as the ‘philosopher of the Arabs’. To al-Kindi, philosophy consisted of three parts, ranked in order of importance: theology, mathematics and physics.

      Al-Kindi remained a devout Muslim all his life. He considered religion and philosophy to be compatible in the same way that reason and revelation are