“Plato, for instance, maintains that the sensation of any object is produced by a perpetual succession of copies, images, or counterfeits streaming off from the object to the organs of sensation. Descartes, too, has explained the matter upon the principle of whirligigs.”
“But does the world exist?” asked the schoolmaster.
“A good deal may be said on both sides,” replied the Doctor, “though the ablest heads are for non-existence.”
“In common cases,” said Uncle Tim, “those who utter nonsense are considered blockheads.”
“But in metaphysics,” said the Doctor, “the case is different.”
“Now all this is hocus pocus to me,” said Aunt Judy, suspending her knitting-work, and scratching her forehead with one of the needles. “I don’t understand a bit more of the business than I did at first.”
“I’ll be bound there is many a learned professor,” said Uncle Tim, “could say the same after spinning a long yarn of metaphysics.”
The Doctor did not admire this gibe at his favourite science.
“That is as the case may be,” said he; “this thing or that thing may be dubious, but what then? Doubt is the beginning of wisdom.”
“No doubt of that,” said my grandfather, beginning to poke the fire, “but when a man has got through his doubting, what does he begin to build upon in the metaphysical way?”