 By including so many caveats and possible but unnecessary characteristics of levels, Wimsatt makes his account extremely versatile and wide in scope, but at the same time open to charges of vagueness or inconsistency (cf. Craver 2007: 182–183). It contains a multitude of criteria that levels could but do not necessarily have to satisfy, so that almost any set of entities that are in some respect similar to one another could be said to form a level. Moreover, the individual criteria as such also raise many questions. For example, how should we understand the “local maxima of regularity and predictability”? What kinds of regularities should we include—only causal generalizations, or also regularities describing associational or compositional relations (Craver 2007: 182–183)? How do we count or estimate the number of regularities on a given scale? How do these peaks match with the other proposed criteria, such as the part-whole organization of levels?