"But it's no use now," thought poor Alice, "to pretend to be two people! Why, there's hardly enough of me left to make one respectable person!" 

- Chapter 1, Down the Rabbit-Hole

"Oh, you ca'n't help that," said the Cat: "we're all mad here. I'm mad. You're mad."
"How do you know I'm mad?" said Alice.
"You must be," said the Cat, "or you wouldn't have come here." 

- Chapter 6, Pig and Pepper