The City and the Stars Page 0,72

"Go down the left-hand ramp," it said. "I will direct you from there."

He walked slowly down the slope, the robot floating above him. Neither Jeserac nor the proctors followed; he wondered if they had received orders to remain here, or whether they had decided that they could supervise him just as well from their vantage point without the bother of making this long descent. Or perhaps they had come as close to the central shrine of Diaspar as they cared to approach.

At the foot of the ramp, the quiet voice redirected Alvin, and he walked between an avenue of sleeping titan shapes. Three times the voice spoke to him again, until presently he knew that he had reached his goal.

The machine before which he was standing was smaller than most of its companions, but he felt dwarfed as he stood beneath it. The five tiers with their sweeping horizontal lines gave the impression of some crouching beast, and looking from it to his own robot Alvin found it hard to believe that both were products of the same evolution, and both described by the same word.

About three feet from the ground a wide transparent panel ran the whole length of the structure. Alvin pressed his forehead agaipst the smooth, curiously warm material and peered into the machine. At first he saw nothing then, by shielding his eyes, he could distinguish thousands of faint points of light hanging in nothingness. They were ranged one beyond the other in a three-dimensional lattice, as strange and as meaningless to him as the stars must have been to ancient man. Though he watched for many minutes, forgetful of the passage of time, the colored lights never moved from their places and their brilliance never changed.

If he could look into his own brain, Alvin realized, it would mean as little to him. The machine seemed inert and motionless because he could not see its thoughts.

For the first time, he began to have some dim understanding of the powers and forces that sustained the city. All his life he had accepted without question the miracle of the synthesizers which age after age provided in an unending stream all the needs of Diaspar. Thousands of times he had watched that act of creation, seldom remembering that somewhere must exist the prototype of that which he had seen come into the world.

As a human mind may dwell for a little while upon a single thought, so the infinitely greater brains which were but a portion of the Central Computer could grasp and hold forever the most intricate ideas. The patterns of all created things were frozen in these eternal minds, needing only the touch of a human will to make them reality.

The world had indeed gone far since, hour upon hour, the first cavemen had patiently chipped their arrowheads and knives from the stubborn stone.

Alvin waited, not caring to speak until he had received some further sign of recognition. He wondered how the Central Computer was aware of his presence, and could see him and hear his voice. Nowhere were there any signs of sense organs-none of the grilles or screens or emotionless crystal eyes through which robots normally had knowledge of the world around them.

"State your problem," said the quiet voice in his ear. It seemed strange that this overwhelming expanse of machinery should sum up its thoughts so softly. Then Allvin realized that he was flattering himself; perhaps not even a millionth part of the Central Computer's brain was dealing with him.

He was just one of the innumerable incidents that came to its simultaneous attention as it watched over Diaspar. It was hard to talk to a presence who filled the whole of the space around you. Alvin's words seemed to die in the empty air as soon as he had uttered them.

"What am I?" he asked.

If he had put that question to one of the information machines in the city, he knew what the reply would have been. Indeed, he had often done so, and they had always answered, "You are a Man." But now he was dealing with an intelligence of an altogether different order, and there was no need for painstaking semantic accuracy. The Central Computer would know what he meant, but that did not mean that it would answer him.

Indeed, the reply was exactly what Alvin had feared.

"I cannot answer that question. To do so would be to reveal the purpose of my builders, and hence to nullify it."

"Then my role was