When we examine a semantic field, or cognitive domain, could there be more regular diachronic patterns in some fields than in others? We might choose to examine, for example, metaphors relating to finance, commerce, technology, law, gastronomy, love, war, religion, or to any other field. Do statements on diachronic patterns depend on the field we wish to investigate? If this is the case, we need to take particular care in the choice of corpus or, better still, to make a comparison of different fields.