Mary Warnock, in her study of imagination (1976), asserted that "the cultivation of imagination...should be the chief aim of education" (p. 9), and that "we have a duty to educate the imagination above all else" (p. 10). We might reasonably feel wary of such bold claims. Though perhaps we need to say first, "It depends what you mean by 'imagination'". It will be obvious that I think it is important to cultivate the imagination, but one of the reasons I have some reluctance in agreeing wholeheartedly with Warnock has to do with the persisting difficulty, despite her admirable work and that of others I will draw on in this book, of getting clear about what imagination is, or about the range of things the word is used to cover. We can begin by observing that people, even those who have been most intimately involved in studying it and promoting its value in education, mean rather different things by the term.