Not only mathematics but astronomy and other sciences were then in alleged conflict with the facts of revelation. Al-Ghazali must have felt this very keenly, for he says: “The ignorant Moslem thinks the best way to defend religion is by rejecting all the exact sciences. Accusing their professors of being astray, he rejects their theories of the eclipses of the sun and moon, and condemns them in the name of religion. These accusations are carried far and wide, they reach the ears of the philosopher who knows that these theories rest on infallible proofs; far from losing confidence in them, he believes, on the contrary, that Islam has ignorance and the denial of scientific proofs for its basis, and his devotion to philosophy increases with his hatred to religion. It is therefore a great injury to religion to suppose that the defense of Islam involves the condemnation of the exact sciences. The religious law contains nothing which approves them or condemns them, and in their turn they make no attack on religion. The words of the Prophet: ‘The sun and moon are two signs of the power of God; they are not eclipsed for the birth or the death of any one; when you see these signs take refuge in prayer, and invoke the name of God’—these words I say, do not in any way condemn the astronomical calculations which define the orbits of these two bodies, their conjunction and opposition according to particular laws.”[26] We must remember in this connection that it was Omar Khayyam, the poet astronomer, who at this very time was leading many into scepticism. After a knowledge of Arabic grammar, and memorizing the Koran, the diligent student would take up its critical and devotional study. Al-Ghazali’s teachers undoubtedly emphasized, as he did himself, the importance of correct reading of the sacred volume. In one of the most beautiful passages in his _Ihya_, Al-Ghazali himself notes the following points: The reader must be clean outwardly, and respect the book with outward reverence. He must read the proper quantity. He quotes with approval the practice of Saʾad and Othman, that the Koran should be read through once a week. One should use chanting (_tartil_), for this is helpful to the memory, and makes us read slowly, and rapid reading is not approved. One should read it with weeping, _i. e._, sorrow for sins. One should give the proper responses in the proper places. One should use the opening prayer before beginning to read. It may be read secretly or aloud. It must be read beautifully—according to the Tradition: “Adorn the Koran by the sweetness of your voice;” or another Tradition: “He who does not sing the Koran is not of our religion.” One day when the Prophet heard Abu Musa reading the Koran he said: “Verily, to this reader God has given the voice of David when he wrote the Psalms.”