By Spider Robinson
A pun by Long Drink, at Callahan's – "Gentlemen, the story I am about to relate takes place in the distant future. Interstellar travel is commonplace; contacts with alien races are familiar experiences. One day, however, a planet is discovered out Antares way whose sole inhabitant is an enormous humanoid, three miles high and made of granite. At first it is mistaken for an immense statue left by some vanished race of giants, for it squats motionless on a yellow plain, exhibiting no outward sign of life. It has legs, but it never rises to walk on them. It has a mouth, but never eats or speaks. It has what appears to be a perfectly functional brain, the size of a four-story condominium, but the organ lies dormant, electrochemical activity at a standstill. Yet it lives.
"This puzzles the heck out of the scientists, who try everything they can think of to get some sign of life from the behemoth – in vain. It just squats, motionless and seemingly thoughtless, until one day a xenobiologist, frustrated beyond endurance, screams, 'How could evolution give legs, mouth and brain to a creature that doesn't use them?"
"It happens that he's the first one to ask a direct question in the thing's presence. It rises with a thunderous rumble to its full height, scattering the clouds, thinks for a second, booms, 'IT COULDN'T,' and squats down again.
"'Great Scott!,' exclaims the xenobiologist, 'Of course! It only stands to reason.'"