A machine, a mechanism, no more than a tool — technological brother to the hoe, the wrench, the hammer — and yet as far a cry from these as the human… - Clifford D. Simak

She looked quickly up. And then her eyes once more went back to the flashing thing she was holding in her hands. He saw that it was the pyramid of spheres and now all the spheres were spinning slowly, in alternating clockwise and counterclockwise motions, and that as they spun they shone and glittered, each in its own particular color, as if there might be, deep inside each one of them, a source of soft, warm light.
Enoch caught his breath at the beauty and the wonder of it — the old, hard wonder of what this thing might be and what it might be meant to do. He had examined it a hundred times or more and had puzzled at it and there had been nothing he could find that was of significance. So far as he could see, it was only something that was meant to be looked at, although there had been that persistent feeling that it had a purpose and that, perhaps, somehow, it was meant to operate.
And now it was in operation. He had tried a hundred times to get it figured out and Lucy had picked it up just once and had got it figured out. He noticed the rapture with which she was regarding it. Was it possible, he wondered, that she knew its purpose?

Jenkins tried to say goodbye, but he could not say goodbye. If he could only weep, he thought, but robots could not weep.

We feel much sorrow for you, the elm tree had said. But what kind of sorrow—a real and sincere sorrow, or the superficial and pedantic sorrow of the immortal for a frail and flickering creature that was about to die?