A Japanese samurai warrior once bragged, "My sword is so sharp that if you bury its hilt in
the bottom of a slowly-moving brook with the blade pointed up and out of the water, leaves
floating by will be cut in two as they encounter its blade."
A second warrior replied, "Ah, but my sword is sharper. If you bury its hilt in the bottom of
a slowly-moving brook with the blade pointed up and out of the water, leaves floating by will
move aside to avoid the blade."