"Tom said to himself that it was not such a hollow world after all. He had discovered a great law of human action without knowing it -- namely that in order to make a man or a boy covet a thing it is only necessary to make the thing difficult to attain. If he had been a great and wise philosopher like the writer of this book he would now have comprehended that Work consists of whatever a body is obliged to do and that Play consists of whatever a body is not obliged to do. And this would help him to understand why constructing artificial flowers or performing on a tread-mill is work while rolling ten-pins or climbing Mont Blanc is only amusement. There are wealthy gentlemen in England who drive four-horse passenger-coaches twenty or thirty miles on a daily line in the summer because the privilege costs them considerable money; but if they were offered wages for the service that would turn it into work and then they would resign."