Ibn Duraid, whose many other names are given by Ibn Khallikan, is described by that author as 'the most accomplished scholar, the ablest philologer, and the first poet of the age.' Masudi and other men of learning also speak of him in the highest terms. He composed several works on natural history, and produced also a complete Dictionary of this kind, after the model of the books 'Al-A'in' and 'Al-Jim,' the two letters of the alphabet with which Khalil, the grammarian, and Abu Amr as Shaibani respectively began their works. Ibn Duraid died at Baghdad A.D. 933. The celebrated Motazelite divine Abu Haslim Abd-as Salam Al-Jubbai died the same day, and this caused the people to say that 'To-day philology and dogmatic theology have ceased to exist.' In the East, by philosophy not only logic and metaphysics are meant, but also all ethical, political, mathematical, and medical sciences. Indeed, it may be said that nearly all learned men were in those days called philosophers, a term which included mathematicians, astronomers, physicians, encyclopaedists and others. From the mass of Arab authors all laying claim to the title of philosopher, it is perhaps an invidious task to select a few only, and even those selected by one person might be rejected by another. But public opinion will probably agree in naming three persons as having claim to the highest rank in Arab learning. They are Al-Kindi, Al-Farabi, and Ali-ibn Sina, commonly called Avicenna. Ali-bin Ridhwan, Al-Ghazali, Ibn Bajah (Avempace), and Ibn Rashid (Averroes) have also their claims to be considered, while Thalab bin Korra, Kosta bin Luka, Al-Tavhidi, and Al-Majridi were also all eminent men. A few details will be given about the first seven of the names just mentioned. Yakub-bin Ishak Al-Kindi, the philosopher of the Arabs, known in Europe by the corrupted name of Alchendius, possessed an encyclopaedic mind, and being himself a living encyclopaedia, he composed one of all the sciences. He divided philosophy into three branches, the mathematical, the physical, and the ethical. He declared the nullity of alchemy, which Ibn Sina had again brought to honourable notice, till the physician Abdul Latif declaimed against it. But Al-Kindi was not sufficiently advanced to write against astrology, which is still in full force all over the East even in our own times. Only one of his works has as yet been published in Europe, and that treats on the composition of medicines, though we possess the titles of not less than two hundred and thirty-four works composed by him on a variety of subjects. He died A.D. 861.