Once, a neighbor stole one of Washington's horses. Washington went with a policeman to get the horse back, but the neighbor refused, claiming it was his own.
Suddenly, Washington had an idea. He covered both of the horse's eyes with his hands and said to the neighbor, "If this is your horse, you must tell us which of its eyes is blind."
"The left eye," said the neighbor. Washington removed his hand from the horse's left eye and showed the policeman that it was not blind.
"Oh, I made a mistake," said the neighbor. "It is blind in the right eye." Washington then showed that the horse was not blind in the right eye, either.
"I have made another mistake," said the neighbor.
"Yes," said the policeman, "and you have also proved that the horse is not yours. You must return it to Mr. Washington."