First published in 1999, this study begins with a review of basic biological functions, stressing the importance to the organism of various kinds of information. The 'biology of information' must consider how the brain reacts to new, as contrasted with expected, inputs; these differences are discussed chiefly in relation to language. In language processing predictability is of prime importance, but to clarify what this entails it is necessary to consider just how our concepts are organized. Personal construct theory throws considerable light on this question, but is less informative about fantasy, which requires separate exploration. The main chapter focuses on the origins and interpretation of metaphor, in which quite disparate concepts are united but which we understand nevertheless. Existing theories of metaphor are unsatisfactory, but personal construct theory again helps resolve the psychological-linguistic issues. Finally, the question is raised as to why a good metaphor produces a response which is recognizably aesthetic in character, and its implications for our aesthetic responses to other art forms are explored.