The origin of the story, The Frog and the Scorpion, might go back to the ancient Sanskrit traditions collected in the Panchatantra, but I first heard the tale while watching a bootleg copy of the 1955 Orson Welles film, Mr. Arkadin forty years ago.
A frog and a scorpion meet on the bank of a stream and the scorpion asks the frog to carry him across on its back. The frog asks, “How do I know you won’t sting me?” And the scorpion says, “Because if I do, I will drown too.”
The frog is satisfied, and they set out. Half way across, the frog felt a terrible pain - the scorpion had stung him.
“Why did you sting me?” gasps the frog. “Now we’ll both die”
“I know,” replied the scorpion, “but I cannot help myself - it is my nature.”
A scorpion’s job, other than to make baby scorpions, is to sting, kill, and eat its prey. If there had been another frog down by the stream bank it might have asked the well intentioned, trusting frog, “What part of sting, kill, and eat didn’t you understand?” But it was just the two of them … the frog and the scorpion down by the stream. And the frog agreed with the scorpion’s irrefutable logic. Why would it cause its own demise? Believing the words of a scorpion, but ignoring the nature of a scorpion, they set off to their mutual doom.