This paper sketches the fundamental characteristics of metaphorical language which enable it to subserve not only the shaping of particular discourses, but also crucial aspects of our powers of enquiry and understanding. It argues that without metaphorical creativity we cannot make adequate sense of the more complex and open-ended aspects of our experience. This is illustrated from the way in which we deploy the closely related key environmental metaphors of "stewardship" and "natural capital", including the more specific "real option" sub-version of the latter idea reported on by other contributions to this Special Issue. But a condition of making such thinking operational and socially productive is the development of a genuine learning society.