Three kinds of transderivational constraint ∗

The status of transderivational constraints (TDCs) in syntactic theory has always been controversial. TDCs – informally definable as any that make syntactic well-formedness dependent upon sets of sentences – were proposed throughout the 1970s in various forms.1 Most were quickly discovered to be factually or theoretically unsound. But this did not lead to a rejection of transderivational thinking. Quite the opposite; TDCs play a bigger role in syntactic theorizing today than ever before. The term itself is in disfavor, but the blocking principles of Di Sciullo and Williams (1987) meet the formal definition (see also Williams 1997; Hankamer and Mikkelsen 2001), as do the economy conditions of Chomsky 1995, Reinhart 1998, Fox 2000, and others working in the Minimalist Program. Despite this current enthusiasm, little work has been done on the underlying logic of these constraints and their consequences for the design and complexity of syntactic theories.2 As a result, all proposed TDC are stated informally, and sometimes their transderivational nature seems not even to be appreciated by their proponents. This paper is a preliminary investigation of the formal properties of TDCs. I show that there are (at least) three logically and conceptually distinct classes of TDC. The tamest of the trio contains only those that can be cast as constraints on grammars, rather than constraints on natural language objects themselves. I call these grammar constraints. They include the metarules of GPSG (Gazdar et al. 1985) and its descendants, blocking principles, and others. Many are context-free definable; in section 3.1 I exemplify using the GPSG passive metarule and a blocking principle for Danish definite marking (Hankamer and Mikkelsen 2001). From a model-theoretic vantage point, grammar constraints place limitations on the constraint set. But most TDCs constrain the constraints themselves, by setting their applicability relative to other sentences (sometimes even non-sentences). These are the true TDCs and the strategies for stating grammar constraints are of no use with them. The true TDCs divide into two subclasses, which I call optional TDCs and intrinsic TDCs.3 Optional TDCs enforce conditions that can be given non-transderivational statements within a more powerful formalism; in