“Why do they move away, then?” asked the backward student, who had by great diligence, after a long time, plodded his way by force of remembering by heart into the top class. He forgot his usual caution and his acquired habit of only asking questions he had heard asked before in order to refresh his memory with the answers he had heard given before. The professor frowned at the stupid question. “The supposed being,” he answered, “while he is attracted to the metropolis in accordance with the general law, may yet have some stronger inducement at the time to move away from the metropolis. That he does move away shows of course that his temporary inducement to move away is stronger than his permanent attraction towards the metropolis.” The student said that he was obliged for the explanation. “But——” “Well?” said the professor. “The only reason you have for supposing that the being is attracted towards the metropolis is that he does move towards the metropolis. I don’t see why you should say it was pleasant for him to move towards the metropolis when he does not do so.” “But we know,” said the professor. “No,” said the student, “you only suppose; because you find it so on a great many occasions, you suppose it is so always. You are like a savage who attacks the house of a civilized man. And he tries the window, the civilized man meets him there; so he tries the door, the civilized man meets him there; so he goes back to the window, and is met there again. And he concludes there are two men in the house; and after a time he concludes there are as many men in the house as there are ways by which he tries to get in.” The student had forgotten himself in speaking like this; and the comparison to a savage, though made in haste and in good part as an illustration, offended the professor, so he said: “You do not believe that the law of attraction towards the metropolis is universal, and affects all the inhabitants?” “I cannot,” said the student. “Then you shall go to a place where you will feel it,” said the professor. “You will go to-morrow to the extreme confines of the valley, and stop there until you are of a different mind.”