  A third option is to appeal to the standards of mathematics itself. Why should one have to appeal to non-mathematical standards, such as those of logic or empirical science, in order to defend the truth of mathematical theorems? When we defend the truth of the claims of logic and physics, we do not need to appeal to standards outside of respectively logic and physics. Rather we assume that logic and physics provide their own sui generis standards of justification. Why should mathematics be any different? This third strategy has received a lot of attention in recent years, often under the heading of ‘naturalism’ or ‘mathematical naturalism’. (See Burgess &amp; Rosen 1997, Maddy 1997, and, for critical discussion, see the entry on  naturalism in the philosophy of mathematics.)