In "The Red Pony", why does Carl say that Jody must never turn the pony into a trick horse?
Carl says that he doesn't like trick horses. He believes "it takes all the - dignity out of a horse to make him do tricks". Carl likens a trick horse to "an actor - no dignity, no character of his own".
Carl makes this comment when he sees the progress Jody has made teaching the pony to work on the long halter. Jody had broken the pony to the short halter first, holding a carrot and "coax(ing) and promis(ing) and pull(ing) on the rope" to get the pony to come. At first the pony had "set his feet like a burro when he felt the strain...but before long he learned", and Jody was able to walk all over the ranch leading him. Gradually, Jody "took to dropping the rope until the pony followed him unled wherever he went".
The work with the long halter was a little different. Jody stood in the middle of a circle, holding the halter, while the pony walked in a big circle held in by a long rope. When Jody clucked with his tongue, the pony would trot, then gallop, "around and around...enjoying it immensely", until Jody called "Whoa", and the pony would stop. The long halter work was "rapidly approaching perfection" when Jody's father stopped by to watch "the pony stop and start and trot and gallop". It was this demonstration that Carl was bothered by, and which prompted him to make the comment about his dislike for trick ponies ("The Gift").