Abstract

This chapter presents arguments positing that there is an important sense in which it takes more than all of the actual kinds to make a world, contrary to the popular saying that goes “it takes all kinds to make a world.” In a variety of ways, the various species of elementary particles are ideal cases of natural kinds since each belongs to exactly one of these natural kinds and it essentially belongs to that kind. There exists perfect uniformities within each species and sharp distinctions between the species with respect to certain properties. Some of these properties are essential and suffice to give necessary and adequate conditions for species-membership, while others derive from the fundamental properties via exceptionless uniformities with no ceteris paribus escape clauses.