BEDEVERE: Tell me … what do you do with witches?

CROWD: Burn them.

BEDEVERE: And what do you burn, apart from witches?

FOURTH VILLAGER: … Wood?

BEDEVERE: So why do witches burn?

SECOND VILLAGER: (quietly) … Because they’re made of wood?

BEDEVERE: Good. So how can we tell if she is made of wood?

FIRST VILLAGER: Make a bridge out of her.

BEDEVERE: Ah … but can you not also make bridges out of stone?

CROWD: Ah. Yes, of course … um … err …

BEDEVERE: Does wood sink in water?

CROWD: No, no, It floats. Throw her in the pond Tie weights on her. To the pond.

BEDEVERE: Wait. Wait … tell me, what also floats on water?

CROWD: Bread? No, no, no. Apples …. gravy … very small rocks …

ARTHUR: A duck.

BEDEVERE: Exactly. So… logically …

FIRST VILLAGER: If she … weighs the same as a duck … she’s made of wood.

BEDEVERE : And therefore?

CROWD: A witch!

—Monty Python and the Holy Grail