The Little Dog Trusty and Other Stories — Maria Edgeworth

Very, very little children must not read this story; for they cannot understand it: they will not know what is meant by a liar and a boy of truth. Very little children, when they are asked a question, say "yes," and "no," without knowing the meaning of the words; but you, children, who can speak quite plain, and who can tell, by words, what you wish for, and what you want, and what you have seen, and what you have done; you who understand what is meant by the words "I have done it," or "I have not," you may read this story; for-you can understand it.