Muller, F.A.http://igitur-archive.library.uu.nl/phys/2011-0301-200642/UUindex.htmlenjournalArticleSpringer2010Crucial to structural realism is the Central Claim that entity B is or has structure S. We argue that neither the set-theoretical nor the category-theoretical conceptions of structure clarify the Claim in a way that serves the needs of structural realism. One of these needs is to have a viable account of reference, which almost any variety of realism needs. There is also a view of structure that can adopt both set-theoretical and category-theoretical conceptions of structure; this is the view that adopts B.C. van Fraassen’s extension of Nelson Goodman’s concept of representation-as from art to science. Yet the ensuing fountain of perspectives is a move away from realism, structural realism included. We then suggest that a new theory of structure is needed, one that takes the word ‘structure’ to express a primitive fundamental concept; the concept of structure should be axiomatised rather than defined in terms of other concepts. We sketch how such a theory can clarify the Central Claim in a manner that serves a descriptivist account of reference, and thereby structural realism.Springer 2010 URN:NBN:NL:UI:10-1874-202128 1 399 416