A locomotive is moving. Someone asks: “What moves it?” A peasant says the devil moves it. Another man says the locomotive moves because its wheels go round. A third asserts that the cause of its movement lies in the smoke which the wind carries away.

The peasant is irrefutable. He has devised a complete explanation. To refute him someone would have to prove to him that there is no devil, or another peasant would have to explain to him that it is not the devil but a German, who moves the locomotive. Only then, as a result of the contradiction, will they