"Behind even so simple a thing as the growing of tomatoes there must be a mass of reasons, certain basic facts. And we do not know these facts. We do not have the knowledge.
"I have wondered what it is that makes the lamps light up when you throw the switch.
"I have wondered what our bodies do with food. How does your body use that tomato you've just eaten? Why must we eat to live? Why must we sleep? How did we learn to talk?"
"I have never thought of all that," said Jon. "You have never thought at all," said Joshua, "or almost not at all."
"No one does," said Jon.
"That is the trouble with the Ship," the old man told him. "No one ever thinks. They while away their time. They never dig for reasons. They never even wonder. Whatever happens must he for the best and that's enough for them."
"I have just begun to think," said Jon.
"There was something you wanted," said the old man. "Some reason that you came."
"It doesn't matter now," said Jon. "You have answered it."
He went back, through the alleyways between the tanks, smelling the scent of green things growing, listening to the gurgle of the water running through the pumps. Back up the long corridors, with the stars shining true and steady now through the ports in the observation blisters.