  The past couple of decades have seen a great surge of interest in naturalism. 1997 was an important year in recent philosophy of mathematics, as it saw the publication of four books articulating the positions of five leading philosophers of mathematics: John Burgess and Gideon Rosen's A Subject with No Object, Penelope Maddy's Naturalism in Mathematics, Michael Resnik's Mathematics as the Science of Patterns, and Stewart Shapiro's Philosophy of Mathematics.  All four books are to various degrees and amongst other things naturalistic: the first two are naturalist manifestos, the third advocates a Quinean scientific naturalism, and the last, though mainly concerned with other matters, is sympathetic to naturalism. John Burgess's naturalism, first set out in his (1983) and in the past few years elaborated with his colleague Gideon Rosen (1997, 2005), is perhaps most naturally construed as a version of mathematical-cum-scientific naturalism (1997, 211). Penelope Maddy's naturalism is a heterogeneous form of naturalism which distinguishes between mathematics proper and the philosophy of mathematics, embracing mathematical naturalism about the former and scientific naturalism about the latter (section 5). Another position suggested by Maddy (1997) is a thoroughgoing mathematical naturalism that takes mathematical standards as authoritative within both mathematics and its philosophy.