Charles Chihara's new book develops a structural view of the nature of mathematics, and uses it to explain a number of striking features of mathematics that have puzzled philosophers for centuries. In particular, this perspective allows Chihara to show that, in order to understand how mathematical systems are applied in science, it is not necessary to assume that its theorems either presuppose mathematical objects or are even true. He also advances several new ways of undermining the Platonic view of mathematics. Anyone working in the field will find much to reward and stimulate them here.