 But not all games of make-believe are like this. Sometimes the games we play and the fictions we generate in the course of playing them owe much of their value and interest to the manner in which they enable us to perceive, conceive, and manipulate their own props. Sometimes our thought and speech about objects that already really exist and are already of vital interest to us can be helpfully structured or restructured by pressing these objects into service as props in a suitable game of make-believe, turning them for the time being into improvised representations of something almost entirely different. Pretend for a moment that Italy is a boot, turn Italy for the time being into an improvised representation of a boot, and you have a readymade scheme for locating particular Italian cities in relation to each other, deriving from familiar established ways of thinking and talking about boots and their component parts. Games of this second sort are prop oriented (Walton 1993). Since little turns on how vividly we imagine the things such games call on us to imagine, we may be only dimly aware of playing them even as we do so. Yet we are are remarkably skilled at playing such games with one another on a pickup basis, never formulating, let alone stipulating, the principles of generation that govern our imaginative collaborations for as long as they last.