A Houyhnhnm is one of a race of intelligent Horses from an island south of Australia (not Tasmania to the east). These horses keep a race of barbaric Humans called "Yahoos", named after the Horses' word for "evil". They also practice eugenics (and possibly racism), they never fall ill, their personality is cold and "perfect", and they never lie. Also, they do not mourn or celebrate death; they dismiss it as a trip to the "First Mother". * By contrast, the "sunny" (and "stormy") Equestrians, or "sapient ponies", are in, many ways like us. They live in a different world, they don't have Humans (shut up, Lyra Heartstrings!), they just accept you whoever you are (unless you're a "monster" like Discord or Queen Chrysalis. Or Krastos.), and they do fall ill and die, in which they wail in sorrows. What if a Houyhnhnm (as enountered by Lemuel Gulliver) meets a Pony in Equestria (or vice versa)? Will they start some sort of flame war, between the Equestrian's changeable emotions, and the Houyhnhnm's cold perfectionism? Though it'll be something nice to watch: what will the Equines do to each other? Please come up with your results! Thanks!
EDIT: * First Mother - a possible Houyhnhnm deity/goddess, alongside "Law and Reason". This might become a strong debate if this falls into Equestrian ears, which comes with the controversial possible interpretation: "THE FIRST MOTHER OF YOURS IS OUR QUEEN FAUST!"