Chomsky’s (1995) theory of movement is mainly based on the determinism in the sense that a derivation is determined by feature- checking under the last resort condition. An alternative theory of movement would be based on the non-determinism in the sense that a derivation is not determined by feature-checking under the last resort condition but accounted for in terms of various interpretive systems. In fact, various attempts for the non-determinism have been proposed even within the deterministic frameworks. For example, even if Chomsky (2008) basically maintains the deterministic basis of feature checking for the theory of movement especially for A-movements, he tries to adopt a non-deterministic approach for some A -movements without much success within his deterministic framework. On the other hand, recently Chomsky (2008) has proposed the notion of “free merge”, which I claim crucially supports the non-determinism even if he does not specifically claim so, probably due to his current deterministic position. This paper shows that the non-determinism based on the theory of unmarked vs. marked internal merge (IM) is more explanatory than the determinism along with the probe-goal feature checking (Chomsky 2000, 2001). The non-determinism based on the theory of unmarked vs. marked internal merge naturally captures the fact that a most significant distinction in movement is the one between unmarked vs. marked internal merge. That is, the unmarked internal merge (IM) is predominant over the marked internal merge across languages. It will be argued that along with the notion of merge the non-determinism is better motivated than the determinism not only for phase-internal optional movements like clause-internal Scrambling in Korean but also for phase-internal obligatory movements like Subject-Raising in English. In fact, it will be claimed that every operation of merge is to induce some new interpretive effects so that the interpretive effects induced by every merge should “justify” the merge itself (EM and IM) (Barbiers 1995). Furthermore, the interpretive effects like topic and focus are not determined by certain head positions (Rizzi 2006) but by the operation of merge itself within the non-determinism. Indeed, the canonical interpretive effect like the scope effect is never dependent on any head. This paper will present a theory of movement in the broader context of the theory of merge, which would contribute to the theory of movement that would conform with the theory of language design (Chomsky 2005). In other words, I will try to answer the question why movement works the way it does through investigation of why merge works the way it does.
1. Determinism vs. Non-Determinism
2. Edge Feature for Merge
3. Unmarked vs. Marked IM
4. Interpretive Effects
5. Syntactic Constraints
6. The Non-Deterministic Grammar