Two sages of Chelm got involved in a deep philosophical argument.
"Since you're so wise," said one, sarcastically, "try to answer this question : Why is it that when a slice of buttered bread falls to the ground, it's bound to fall on the buttered side?"
But as the other sage was a bit of a scientist he decided to disprove this theory by a practical experiment. He went and buttered a slice of bread. Then he dropped it.
"There you are! " he cried triumphantly. "The bread, as you see, hasn't fallen on its buttered side at all. So where is your theory now? "
"Ho-ho! " laughed the other, derisively. "You think you're smart! You buttered the bread on the wrong side! "