Go to the stable

Three Greek philosophers and an Arab were all staying at the same inn. At dinner the philosophers were discussing the number of teeth in a horse's head. Each philosopher mustered his best arguments and debated the subject at length, using reason and logic to validate their claim. The first philosopher insisted that horses have 32 teeth; the second 40 teeth; and the third 48. Eventually, unable to reach agreement, the philosophers called upon the Arab to adjudicate. 

The Arab bowed, left the room and after a few moments returned and pronounced in favor of the second philosopher. All of the philosophers sprang to their feet and demanded to know which of his arguments had swayed him.

The Arab responded “Arguments? I went into the stable and counted”.