VI.
Several sayings of Al-Hasan bin Sahl, the vizier to the Khalif Al-Mamun, have been preserved. Once he himself wrote at the end of a letter of recommendation, dictated to his secretary: 'I have been told that on the day of judgment a man will be questioned respecting the use he made of the influence given him by his rank in the world, in the same manner as he will be questioned respecting the use he made of the superfluity of his wealth.'
Again he said to his sons: 'My sons, learn the use of language; it is by it that man holds his preeminence over other animals; the higher the skill which you attain in the use of language, the nearer you approach to the ideal of human nature.'