Science Without Numbers caused a stir in philosophy on its original publication in 1980, with its bold nominalist approach to the ontology of mathematics and science. Hartry Field argues that we can explain the utility of mathematics without assuming it true. Part of the argument is that good mathematics has a special feature ( conservativeness ) that allows it to be applied to nominalistic claims (roughly, those neutral to the existence of mathematical entities) in a way that generates nominalistic consequences more easily without generating any new ones. There has been much debate about the book since it first appeared. It is now reissued in a revised contains a substantial new preface giving the author’s current views on the original book and the issues that were raised in the subsequent discussion of it.