Chisholm starts his argument by sketching some outlandish examples, but then he turns to a familiar case. He asks us to consider a pair of tables, x and y. Each table is made of smaller parts. Just as he did in the case of Adam and Noah, Chisholm imagines a series of small changes. Instead of gradual changes of properties, he here imagines gradual changes of parts. First, he describes a possible in world in which x and y have exchanged one small part. Then he describes further possible worlds in which more small parts are exchanged. At last we reach a possible world in which x and y have exchanged all their parts: everything that is actually a part of x has now become a part of y; and everything that is actually a part of y has now become a part of x.