1In the same years that Ibn al-Haytham sat in his dark room in Cairo, another man was running for his life across Persia. He ran for most of thirty years. And as he ran he wrote, on horseback, in hiding, in prison, by any lamp he could find, until he had written down nearly everything that was then known about the healing of the human body.
2His name was Abu Ali al-Husayn, son of Abdallah, son of Sina. The west would call him Avicenna. His pupil called him the Master, and it is the pupil who tells this story.
3The pupil's name was al-Juzjani. He was not a great man and he knew it. He had one gift, which was that he knew a great man when he met one, and he met his in the town of Gurgan by the Caspian Sea, and he did not leave his side for twenty-five years.
4"I was his shadow," al-Juzjani said when he was old. "A shadow does not do much. But it is some proof that a man was there, and stood in the light."
5On the night this story begins, the two of them were in a cellar in the city of Hamadan, cutting up a wool blanket.
6The Master had been vizier of that city, chief minister to its prince. He had been a good one, which made him enemies. The soldiers had risen against him once and sacked his house and shouted for his head. Then the old prince died, and the new prince's minister found letters that the Master had written in secret to the lord of Isfahan, asking for shelter.
7For that he had been shut in a fortress on a rock for four months. At the gate of it he had made a verse, and laughed as he made it: that his going in was plain enough for anyone to see, and all the doubt was about his coming out.
8He came out. But he came out into a city where every door was watched. So now he sat in a druggist's cellar among jars of rhubarb root, and al-Juzjani cut the blanket into the rough patched robes that wandering holy men wear, the Sufis, who own nothing and go where they like and whom no guard troubles to search.
9There were five of them to go: the Master, his brother, al-Juzjani, and two serving men. The Master tried on his robe. He was forty-three, broad in the chest, with a vizier's beard.
10"You do not look like a man who has renounced the world," said al-Juzjani.
11"I have renounced Hamadan," said the Master. "It will have to do."
12They went out through the south gate at dawn, among the market people, with their heads down and their feet bare. A guard looked at them and yawned. Then they were on the road, with Isfahan twelve days ahead and all the horsemen of Hamadan behind.
13Now hear, while they walk, how this man came to be on that road.
14He was born near Bukhara, beyond the Oxus, in the far north-east of the lands of Islam. By ten he had the whole Quran by heart. By sixteen he was teaching medicine to grown physicians. He said himself that medicine was not one of the hard sciences, and that is the sort of thing he said, and it did not make him loved.
15But this must be told of him also. There was a book he could not understand. It was the deepest book of the Greek master Aristotle, on what lies behind all things. He read it forty times. He had it by heart and still it was a locked house to him. In those days, when a question would not open, he would go to the mosque and pray, and ask the Maker of all things to open it; and he would go home and light the lamp and try again.
16One afternoon in the booksellers' market a man was crying a small book for sale, cheap. The boy waved him off. The seller ran after him. "Buy it! The owner needs the money. Three dirhams!" He bought it to be rid of the man. It was a little work by an older Muslim thinker, al-Farabi, explaining that very book of Aristotle. He read it standing in the street. The locked house opened room by room. The next morning he gave alms to the poor in thanks to God.
17When he was seventeen the prince of Bukhara fell sick, and the court physicians could not mend him. They sent for the boy. He mended him. And for his fee he asked one thing only: to be let into the prince's library.
18He read there for a year and a half as a starving man eats. Then the library burned. No one knew how. And soon after, the princes of Bukhara fell to their enemies, and the boy who had read the library was a young man with no patron, carrying the library in his head.
19He went west to the city of Gurganj, where there was a court that loved learning. He had a friend there, an older man, a physician. His name was Abu Sahl, and he was called al-Masihi, the Christian, for that was his faith. They worked side by side for years, the Muslim and the Christian, and argued about the pulse.
20But a new power was rising in the east: Mahmud of Ghazna, a great taker of cities. Mahmud collected scholars as other kings collect hawks. He wrote to the lord of Gurganj: Send me your wise men. It was not a request.
21Some went. The Master would not be a hawk on any man's wrist. He and his friend the Christian left the city by night, with a guide, and went into the desert of black sand that lies to the south.
22"It is told," said al-Juzjani, "though I was not there, that on the fourth day a wind got up out of the north. The sand stood up and walked. They lost the guide. They lost the track. Abu Sahl was not young, and the heat and the thirst took him. He died in the Master's arms in the lee of a dune, and the Master dug the grave with his hands, and said over a Christian what words he had, and went on alone."
23He never spoke of it. But in the great book of medicine, the Canon, where he set down the healing knowledge of the Greeks and the Persians and the Indians, he set down things that he had from his friend. A man can be buried in the sand and still be found in a book.
24Now the five false holy men walked south. And al-Juzjani's fear on that road was not the horsemen. It was the Master himself. For there was one thing in the world the man could not do, and that was pass by a sick person.
25On the fourth night they came to a caravanserai, a walled inn of the road, and it was full. There were mule drivers there, and merchants. And there were eight soldiers of Hamadan with their horses, who had been sent down the Isfahan road to look for a runaway vizier.
26The five sat in the darkest corner and ate their bread. In the middle of the night a woman began to scream.
27It was a mule driver's wife. Her child, a boy of three, was choking. His throat had swollen shut with a sickness of the throat, and his lips were going blue, and his breath came in with a thin sound like a wet reed. The mule driver ran from sleeper to sleeper, begging. Was anyone a physician? Did anyone know a charm? The merchants pulled their cloaks over their heads.
28Al-Juzjani felt the Master move beside him. He took hold of his sleeve with both hands.
29"Master," he whispered. "There is no other man in Persia who could save that child. They know it. The moment you do it, you have written your name on the wall."
30"Yes," said the Master.
31"They will take you back to the rock. This time you will not come out."
32"That may be."
33"Think of the books! The Canon is not finished. The great book on the sciences is not finished. If you die on that rock, they die with you. Ten thousand people not yet born will go unhealed for want of what is in your head. Count them! Weigh them against one mule driver's boy!"
34The Master took the pupil's hands from his sleeve, gently. "You have been with me ten years," he said, "and you still think the book is the thing. The book is not the thing. That is the thing." He pointed at the sound of the child. "The book is only how I reach the ones I cannot walk to. I can walk to this one."
35He got up. He went across the courtyard in his blanket robe and knelt by the child, and he was no longer a holy beggar. Anyone could see it. His hands knew exactly where to go.
36He called for a lamp, a spoon, hot water, a reed. He bent the child's head back and looked into the throat. He did there, by one bad lamp, what he afterward wrote down in the Canon for the worst cases of the closing throat, when all else has failed: he made a road for the breath. It was quickly done. The thin whistle stopped. The child's chest heaved, and the blue went out of his lips, and he began to cry aloud, which is the best sound a physician ever hears.
37When the light came, the sergeant of the soldiers was standing over him. He was a grey man with a scar. He had watched the whole of it from his blanket.
38"That was well done, dervish," said the sergeant.
39"God is the healer," said the Master. "I only cleared the road."
40"I have seen that done once before," the sergeant said. "In Hamadan. Six years ago, in the fever summer. There was a vizier there who used to come down to the soldiers' quarter after his day's work and physic our children for nothing. Then we were told he was a traitor, and we broke his house." He looked at the child. "I helped to break it. I have thought about that."
41"We were sent to find that vizier," the sergeant said. "A fat man in silk, we were told, with a train of servants. I have looked. I have seen no vizier on this road. Only five beggars and a sick child." He turned to go. Over his shoulder he said, "The left fork is shorter, and there are no posts on it. Go with God."
42They took the left fork. They went hungry on it, and were robbed once, and came into Isfahan at last with their feet bleeding. The lord of that city sent out his own friends to meet the Master, with robes and horses, and gave him a house, and there for some years he was at peace.
43It was there that al-Juzjani won the only argument he ever won.
44"Write it down," he said. "All of it. Not for the prince. For the physician in a village who has no one to ask."
45"I have no time."
46"You have nights. I will hold the lamp."
47So the Master wrote, and the shadow held the lamp. Each night, when the court was done with him, the pupils came to his house. One read aloud from the great book on the sciences, and one from the Canon, turn and turn about, and he corrected and went on.
48In the Canon he gathered what Galen the Greek had taught, and what the physicians of India had taught, and what the old Persian healers knew, and what his Christian friend had shown him, and what he had seen with his own eyes at ten thousand bedsides. He did not ask where a cure had been born. He asked whether it worked. He wrote that a medicine must be tried on the plain sickness and not the tangled one, and tried many times and not once, for what happens once may be chance.
49He wrote that some sicknesses pass from one person to another, and that water and earth can carry them. He wrote that grief can waste a body as surely as fever, and it is told that he once found the cause of a young man's wasting by holding his wrist and speaking aloud the names of streets, until the pulse leapt at one street, and one house, and one name.
50He did not spare himself. He worked all day for the prince and half the night for the book, and al-Juzjani begged him to rest. He answered that he would rather have a life that was wide than one that was long. It is one of the few things he was wrong about. He had neither. He was struck down by a sickness of the bowel on a march, and treated himself too fiercely, and he knew before anyone that he was beaten.
51He told those about him, calmly, as he would have told it of any patient, that the governor which had governed his body could govern it no longer, and that treatment was of no more use. He was fifty-seven.
52In his last days he put away his books. He gave what he owned to the poor. He set his slaves free. He had the Quran read to him from beginning to end, again and again, and he died in the holy month, in Hamadan, the city that had hunted him. His grave is there still.
53Al-Juzjani gathered the pages. That was his work, and he did it for the rest of his life. He put in order what the Master had left in disorder. He finished the story of the Master's life where the Master had left off telling it. A shadow does not do much.
54The Canon went east to India and west to Spain. It was put into Latin, and into Hebrew. For six hundred years, in lands that fought each other over everything else, a physician who was called to a choking child at midnight would reach for the same book. Most of them never knew where Bukhara was.
55And somewhere on the road to Isfahan a mule driver's son grew up, and grew old, with a small white scar at the base of his throat. He told his grandchildren that a holy beggar had put it there. It was the only thing he had wrong.
56Now hear what came after.