Nominalism and Non-Atomic Systems
M. G. Yoes · Noûs · 1967
1. Goodman's criterion of nominalism for systems is an identity condition for individuals which is framed in terms of the notion of a generating relation.2 Nominalistic systems in this sense are contrasted with systems which make essential use of the notion of a class. This means that the generating relation G can be identified with the logical sum of tlhe proper part relation and the proper ancestral of the membership relation.3 The crucial identity condition which is the mainspring of Goodman's nominalism is a precise formulation of the intuitive idea that there is no distinction between objects without a difference of content. It requires definitions of 'is an atom' and 'is an atom of' in terms of G. An atom is simply something to which nothing bears G.