Why did the chicken cross the road?

...

Machiavelli:          So that its subjects will view it with admiration,
                      as a chicken which has the daring and courage to
                      boldly cross the road, but also with fear, for whom
                      among them has the strength to contend with such a
                      paragon of avian virtue?  In such a manner is the
                      princely chicken's dominion maintained.
...

Johann von Goethe:    The eternal hen-principle made it do it.