Two kinds of variation in a minimalist system

This paper reconsiders the status of parameters and parametric variation from the perspective of recent developments within the minimalist program, in particular the problem that arises if parameters can no longer be part of UG, which must be maximally empty, and if variation is instead to be explained in terms of third-factor considerations (section 1). I pursue the idea that variation arises precisely because UG is maximally underspecified, thus leaving many options open (Biberauer & Richards 2006, Berwick & Chomsky 2008, Boeckx 2008). Adopting the asymmetric view of language design put forward in Chomsky 2005a, 2006 and Berwick & Chomsky 2008, whereby language is optimally designed only for satisfying conditions imposed by the semantic interface, I identify two kinds of variation corresponding to the two domains in which indeterminacies may arise in a minimalist architecture with a minimally specified UG: (i) within the narrow syntax or (ii) at the phonological (sensorimotor) interface (‘externalization’, the mapping to PF). In (i), the domain of the Strong Minimalist Thesis (SMT) and thus of a parameter-free UG, free variation is predicted to occur, with each ‘competing option’ a possible choice in every derivation (section 3). In (ii), to which the SMT does not apply, competing options are resolved consistently in a language through parametric choices, yielding macroparametric variation (directionality, polysynthesis) at the PF-interface (section 2).