A traveler stayed for the night with an old man. In the morning, as he was preparing to leave, he asked the old man, "What is a brick?"
The old man gave him a funny look, but said, "A brick is a hard, red object."
The traveler thanked him and went thoughtfully on his way. He stayed, the next night, with an old woman. In the morning, as he prepared to leave, he asked her, "What is a brick?"
She tilted her head and squinted at him, then said, "A brick is a block of clay, fired in a kiln."
The traveler thanked her, and on his way, wondered which one of his hosts had been right, and hoping that the next one would settle the question. That night, he wearily arrived at the house of a young man who gave him shelter. In the morning, just before leaving, he asked, "What is a brick?"
The young man smiled condescendingly and answered, "A brick is what you use to build a wall."
The traveler thanked him, and resumed his journey. As he walked, he said to himself, "What fools these people are, that they cannot tell me this."