On the Relaxation of Intervention Effects
On the basis of insights captured in Rizzi’s (1990) Relativized Minimality, Chomsky (2000, 2001, 2004) proposes the Defective Intervention Constraint in (1) (adapted from Chomsky 2000, 123).
This constraint is appropriate as a first approximation, but certain anomalies remain unaccounted for (see, e.g., Rizzi 2004). In this chapter, I will focus on the Wh-Island Constraint imposed on wh-movement.
The Wh-Island Constraint, exemplified by (2a–b), has been widely assumed to be a defective intervention effect of type (1).
Let us consider (2a). During its derivation, we come to the stage where the Q-feature of the matrix C, being a probe, seeks a goal.
In (3), the wh-phrase when raises to the specifier position (Spec) of the embedded C for checking purposes. The Q-feature of the embedded C and the wh-feature of when, both of which are uninterpretable, are deleted (valued). Given that uninterpretable features render the goal active, when, whose uninterpretable wh-feature has been deleted (valued), is not active as a goal. When the Q-feature of the matrix C seeks a goal, when blocks movement of which of the new books to the Spec of the matrix C as a result of the Defective Intervention Constraint (1). This is because when, which is not active but visible, c-commands which and thus functions as an intervener.
I will show, however, that the wh-island effects are relaxed when the following two conditions are met: (1) indirect questions are infinitive or subjunctive, and (2) extracted wh-phrases are D(iscourse)-linked. I will argue that this hitherto unexplained anomaly concerning the Wh-Island Constraint is given a principled minimalist account by an operation of covert restructuring and the Phase Impenetrability Condition (PIC) proposed by Chomsky (2000, 2001, 2004). I will show that contrary to the widespread view that the Wh-Island Constraint can be subsumed under the Defective Intervention Constraint (1), we still need a traditional Subjacency-type account like that advocated by Chomsky (1973, 1977, 1986) to fully accommodate the wh-island effects.
