Alfarabi, Muhammad Ben Tarkhan Abu Nasr Alfarabi, was born at Farb (now Otrar) toward the end of the ninth century of our era. Though of Turkish descent, he received his philosophical training under the tutorship of the Christian philosopher, Yuhanna Ben Hailan. Later he went to Baghdad, at that time the center of Greek philosophy. Going to Aleppo, he lived at the court of Seif-Eddaula Ali Ben Hamdan, arousing the admiration of all by his skill in dialectics. After a lengthy stay at Aleppo he went to Damascus with his patron, where he died in December of the year 950 A.D.
In logic he wrote Introduction to Logic and Abridgment of Logic. In the natural sciences he wrote commentaries on Aristotle's Physics, Meteorology, De Coelo et Mundo. He also wrote an essay on The Movement of the Heavenly Spheres.
In Psychology he wrote a commentary on Alexander of Aphrodisias' De Anima as well as various treatises on the Soul, the Power of the Soul, the Unity and the One, on the Intelligence and the Intelligible (i.e. on the various meanings of the word "intellect" as found in Aristotle.)
In Metaphysics he wrote essays on Substance, Time, Space and Measure, and various treatises entitled The Gems of Wisdom, A Letter in Reply to Certain Questions, The Sources of Questions, The Knowledge of the Creator.
In Ethics he wrote a commentary on the Nicomachean Ethics of Aristotle. Of his original works the following are best known:
Encyclopedia, in which he gives a brief account and definition of all branches of science and art.
Political Regime, which is known as the Book of Principles. The reading of this book is recommended by Maimonides in these terms: "I recommend you to read no works on Logic other than those of the philosopher Abu Nasr Alfarabi, since all that he wrote, especially the Book of Principles, is as fine flour."