It is precisely because mathematics is conservative that, despite being false, it can be useful. Of course, this usefulness is explained with no commitment to mathematical entities: mathematics is useful because it shortens our derivations. After all, if a mathematical theory M is conservative, then a nominalistic assertion A about the physical world (i.e. an assertion which does not refer to mathematical objects) follows from a body N of such assertions and M only if it follows from N alone. That is, provided we have a sufficiently rich body of nominalistic assertions, the use of mathematics does not yield any new nominalistic consequences. Mathematics is only a useful instrument to help us in the derivations.