I know why you did it too. You can't become mortal yourself until you change her...

I know why you did it too. You can't become mortal yourself until you change her back again. Isn't that it? You don't care what happens to her, or to the others, just as long as you become a real magician, even if you change the Bull into a bullfrog, because it's still just a trick when you do it. You don't care about anything but magic, and what kind of magician is that? Schmendrick, I don't feel good. I have to sit down."
Schmendrick must have carried her for a time, because she was definitely not walking and his green eyes were ringing in her head. "That's right. Nothing but magic matters to me. I would round up unicorns for Haggard myself if it would heighten my power but half a hair. It's true. I have no preferences and no loyalties. I have only magic." His voice was hard and sad.
"Really?" she asked, rocking dreamily in her terror, watching the brightness flowing by. "That's awful." She was very impressed. "Are you really like that?"
"No," he said, then or later. "No, it's not true. How could I be like that, and still have all these troubles?" Then he said, "Molly, you have to walk now.