"God the Unique Being and Source of all that exists--angels, intelligences exempt from connection with matter, souls united to matter, elements in all their varied developments--animal, vegetable and mineral, inspires His whole creation, and His omniscience embraces all. His influence in the first place acts immediately on the Active Intelligences and angels, who in their turn act on souls which in their turn act on our sublunary world. If there were not homogeneity of substance between celestial and terrestrial souls and likeness between the macrocosm of the universe, and the microcosm of man, the knowledge of God would be impossible for us, as the Prophet himself hath said, 'He who knows himself, knows God.' All creation, whose parts are linked together, is subject to influences which all derive from a single source--God. Terrestrial souls differ widely in rank; the highest are endowed with gifts of prophecy, and perfected so far that they attain the sphere of pure intelligence. A soul of this kind entering after death into eternal beatitude, shared with its peers, continues along with them to exercise a certain influence on terrestrial souls. The object of prayer for the dead and visiting their tombs is to beg for the help of those pure souls, a help which is realised sometimes in a material, sometimes in a spiritual way. The former kind of help may be compared with the direction which the body receives from the brain; spiritual assistance is realised by the purification of the mind from every thought but that of God." Avicenna, after his liberation from imprisonment by Ala-ed-Dowla, being anxious to quit Hamadan, left the city secretly with his brother, his disciple Joujani and two servants, all five disguised as Sufis. After a painful journey they reached Ispahan, where they were received in a friendly manner by Ala-ed-Dowla. Avicenna here continued to hold philosophical discussions as he had done at Hamadan. At Ispahan he also composed two of his most important works, the "Shifa" and the "Najat," treating of medicine. Later on he followed Ala-ed-Dowla to Bagdad, but on the way was seized with a gastric malady, accompanied by an attack of apoplexy. He recovered at the time, but not long afterwards the sickness returned, and he died at the age of 57, A.D. 1037. In his Literary History of Persia (vo. II., p. 108) Professor Browne points out that one of the most celebrated stanzas in Fitzgerald's translation of Omar Khayyam was really composed by Avicenna:-- "Up from earth's centre through the Seventh Gate I rose, and on the throne of Saturn sate, And many a knot unravelled by the road, But not the master-knot of human fate." Another interesting link between the two philosophers is supplied by the fact, mentioned by Professor Browne, that a few days before his death Omar Khayyam was reading in the "Shifa" of Avicenna the chapter treating of the One and of the Many.