Based on the observation that the possibility for dialogue depends on the conceptual systems of the people engaged in it, the author addresses two areas where conceptual systems can differ: conceptual metaphor and folk theories. Methaphorical concepts are those which are understood and structured not on their own terms, but in terms of other concepts (e.g. `more' being expressed as `up'), and the folk theories are to be seen as models af some aspects of reality that are most often taken as constituting`common sense'.