 This next distinction concerns the role the modal fiction is to play in the theory. Is the fiction of possible worlds intended to provide an explanation of the applicability modal vocabulary, or not? The view that the truth of modal claims depends on, or is to be explained by, the contents of the fiction of possible worlds is often called “strong modal fictionalism”, following Rosen’s description of such a view (Rosen 1990, p. 354, Nolan 1997a). The view that modal truth does not depend on the contents of the modal fiction (and usually, that what the contents of the modal fiction are depends on the modal truth), on the other hand, is known as “timid modal fictionalism”, again following Rosen (Rosen 1990, p. 354).