"We are proposing that the concepts that occur in metaphorical definitions are those that correspond to natural kinds of experience." (#60 2056)

"the following would be examples of concepts for natural kinds of experience in our culture: LOVE, TIME, IDEAS, UNDERSTANDING, ARGUMENTS, LABOR, HAPPINESS, HEALTH, CONTROL, STATUS, MORALITY, etc. These are concepts that require metaphorical definition, since they are not clearly enough delineated in their own terms to satisfy the purposes of our day-to-day functioning." (#60 2057)

"we would suggest that concepts that are used in metaphorical definitions to define other concepts also correspond to natural kinds of experience. Examples are PHYSICAL ORIENTATIONS, OBJECTS, SUBSTANCES, SEEING, JOURNEYS, WAR, MADNESS, FOOD, BUILDINGS, etc." (#60 2060)