One of the Knights of the Round Table in Monty Python and the Holy Grail. The smart one. Perhaps best known for proving that one can identify a witch by showing they weight as much as a duck.
The proof goes a little something like this:
Therefore, witches are made of wood.
- Wood floats.
- Ducks float (also very small rocks).
So if someone weights as much as a duck, they must be a witch.
QED.