Violable principles and typological variation

In the Government-based literature, all structural principles supplied by UG are, without exception, assumed to exert their influence over every well-formed representation. We do find cases, however, where two principles that appear to be universally applicable make opposing predictions as to the grammaticality of a given structure. To resolve such instances of principle clash, I propose a localised form of principle ranking whereby a principle may be violated in order to allow a more highly ranked principle to make its contribution to grammaticality. I show how the incorporation of ranking into a principles-based model can make useful predictions concerning typological variation within ATR harmony systems. 1 Grammaticality as structural well-formedness From the assumption that phonological processes play a role in determining the overall shape of representations, it follows that one of the primary functions of an explanatory theory must be to impose limits on the ways in which a structure can be manipulated by the phonology. Without establishing such limits, a theory would inevitably fail to account for the finite nature of phonological knowledge. However, this task of defining the boundaries of structural change presupposes a more fundamental role undertaken by the grammar — that of predicting the form of a possible representation. Specifically, a grammar must establish what kinds of structure may potentially serve as the input to, and the output of, a phonological operation. Indeed, the capacity for distinguishing between well-formed and ill-formed structures is traditionally seen as the cornerstone of the generative view of language. Here I maintain this basic tenet of the generative approach, where the grammar is presented as a device for creating well-formed representations to the exclusion of