So early as the twelfth century the astronomer-poet of Persia, Omar Khayyam, of Naishapur, in his few hundred tetrastichs of exquisite verse which have ever since won the admiration of the world, struck the note of dreary scepticism and epicurean sensuality, as the Roman Lucretius had done. His age was one of spiritual darkness, when men felt their misery, and all the more that they saw no means of relieving it. The purer creed of Zoroaster had been stamped down but not rooted out by the illiterate Arab hordes of Mohammed. A cultured Aryan race could not accept submissively the ignorant fanaticism of the Semitic sons of the desert. The Arabs destroyed or drove out ultimately to India the fire-worshippers who had courage to prefer their faith to the Koran; the mass of the people and their leaders worked out the superficial Mohammedanism identified with the name and the sufferings of Ali. The new national religion became more and more a falsehood, alike misrepresenting the moral facts and the character and claims of God, and not really believed in by the general conscience. The few who from time to time arose endowed with spiritual fervour or poetic fire, found no vent through the popular religion, and no satisfaction for the aching void of the heart. The loftier natures ran by an inevitable law of the human mind either into such self-indulgent despairing scepticism as Omar Khayyam's, or into the sensual mysticism of Sadi, Jami, and Hafiz, of the whole tribe of ascetic enthusiasts and impostors, the Soofis, fakeers, and durweshes, who fill the world of Islam, from the mosques on the Bosporus to the secret chambers of Persia and Oudh. To all such we may use one of the few rare tetrastichs which Omar Khayyam was compelled by his higher nature to write:[55] O heart! wert thou pure from the body's dust, Thou shouldest soar naked spirit above the sky; Highest heaven is thy native seat--for shame, for shame, That thou shouldest stoop to dwell in a city of clay!