An engineer, an experimental physicist, a theoretical physicist, and a philosopher are taking a walk through the Scottish highlands when they come across a black sheep. The engineer blurts out “hey look, the sheep in Scotland are black!” The experimental physicist turns to him and says “some of the sheep in Scotland are black.” The theoretical physicist, looking bemused, chuckles and says “actually, at least one of the sheep in Scotland is black.” The philosopher, who had been kneeling to examine a flower, looks up and says “on one side, anyway.”