You know the fable of the Scorpion and the Frog, don't you? A scorpion asks a frog to carry it across a river; the frog refuses, knowing that the scorpion will sting it; the scorpion declares that it wouldn't be in its interest to do that because then they both would die in the river; the frog consents, and halfway across the scorpion stings it anyway. As they sink below the water, the frog asks why, and the scorpion replies, "I can't help it -- it's my nature."
Today I overheard one old man telling this story to another old man; the second man had never heard it before, which made me feel better that I hadn't known it before Forest Whitaker told it in The Crying Game thirty years ago. The storyteller today made an odd change to the story: in his version the frog was a turtle. But the outcome was the same: the scorpion stings, both die. (The story does not, as Internet folkore may tell you, date back to Aesop. There may be versions which pit a turtle against the scorpion, but they apparently have different outcomes.)
Maybe I should have asked him about it, but I was more interested in how I thought the ending should have changed. The scorpion stings the turtle, the turtle keeps on going. The scorpion says, "Wait, I just stung you, why aren't you dying along with me in the water?"
The turtle replies, "I'm a turtle, not a frog; I didn't feel a thing. But since you tried to kill me, I'll just throw you off and let you drown."
"No!" wails the scorpion. "I was acting according to my nature! It's not fair that you should let me die! What about my life?"
"Life is unfair," says the turtle, as it ducks quickly under the water. The scorpion is washed off into the current and drowns. The turtle climbs out onto the opposite bank and lives happily ever after.
What the original story means depends on who each character is made to represent. Five years ago the capitalist propaganda outlet Forbes published an article which hilariously cast Big Government as the scorpion, Free-Market Entrepreneurs as the frog, and Larry Kudlow as a wise sage. The idea, however, seems to be that Free Enterprise is a brutal fight between scorpions who turn into tender frogs if they let the Dang Gommint step in as referee. (I know: What? The writer, who modestly bills himself "one of the leading tax experts in the political world today," can't even use a metaphor consistently.) In this blog post, the scorpion is a business owner who just has to sell, no matter what - but that's a good thing. A concern-trolling article at Daily Kos warned Congressional Republicans that they are the frog and Donald Trump is the scorpion. And so on.
My modified version, of course, is also an interpretation, and reflects my biases. I agree with these writers, who appear to be Randites (they quote the prophetess' word as Scripture) that the fable doesn't accurately reflect human nature, but I don't agree that human nature is a tabula rasa, which isn't necessary to make their point: that human beings can make choices. One could also point out that the fable's message is about interactions between human beings, not different species. In Rand's mythology rational individualists are at war with collectivist parasites, with whom they seem not to share a common nature. But that's how animal fables work: human traits are assigned to different species.
Independently of this tale, we're commonly told that human nature makes us scorpions or frogs. There are winners and losers, elites and the canaille, superior richies and inferior Poors, "those who make great demands on themselves, piling up difficulties and duties; and those who demand nothing special of themselves, but for whom to live is to be every moment what they already are; without imposing on themselves toward perfection". Those who ride on the backs of others, stingers at the ready, comfort themselves with the belief that it's their nature to be on top. No one knows where individual differences in temperament come from, but they're not set in stone. The turtle can throw the scorpion off.