THE TIME MACHINE
controvert one or two ideas that are almost universally accepted. The geometry, for instance, they taught you at school is founded on a misconception."
"Is not that rather a large thing to expect us to begin upon?" said Filby, an argumentative person with red hair.
"I do not mean to ask you to accept anything without reasonable ground for it. You will soon admit as much as I need from you. You know of course that a mathematical line, a line of thickness nil, has no real existence. They taught you that? Neither has a mathematical plane. These things are mere abstractions."
"That is all right," said the Psychologist.
"Nor, having only length, breadth, and thickness, can a cube have a real existence."
"There I object," said Filby. "Of course a solid body may exist. All real things———"
"So most people think. But wait a moment. Can an instantaneous cube exist?"
"Don't follow you," said Filby.
"Can a cube that does not last for any time at all, have a real existence?"
Filby became pensive. "Clearly," the Time Traveller proceeded, "any real body must have extension in four directions: it must have Length,
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