Contemporary generative syntactic theory is recast in terms of the mathematical theory of partial orders and order-preserving mappings. Phrase markers are shown to be sets of syntactic objects partially ordered by set-theoretic containment, and by a formal relation analogous to traditional asymmetric c-command. Complete sentential structures are sets of phrase markers related by merger and movement transformations, both of which are order-preserving mappings. The elaborated framework is used to provide a novel perspective on so-called phrase structure paradoxes. In conjunction with recent substantive insights concerning the nature of syntactic derivation, interpretive binding theory and VP-external merger of prepositions, a simple, unified account of the paradox is provided, avoiding problematic aspects of previous accounts.