A theoretical survey is presented, introducing a distinction between structural and functional characterizations of metaphor. Although conclusions must be qualified, the present analysis suggests that (a) nominal, predicative, and perhaps sentential metaphors are psychologically distinct for children and adults, (b) different types of metaphor are related to judgments of similarity, although theories differ in their emphasis on this relation, (c) fantasy and magical interpretations of language are related to metaphor during development, and perhaps during metaphorical interpretation by adults, and (d) functionally distinct classes of metaphor, such as those defined as "elite" and "mundane," may require different theoretical principles. (Valerie Reyna)