From Aspects' “Daughterless Mothers” (aka Delta Nodes) to POP's “Motherless Sets” (aka Non-Projection)

In this chapter, Epstein, Kitahara, and Seely (EKS) selectively summarize the theory of human syntactic generation and representation from Chomsky (1965) Aspects, to X’ theory, continuing to the Minimalist Program for Linguistic Theory (MPLT), Bare-phrase structure (BPS), the Strong Minimalist Thesis (SMT), and up to Chomsky (2015) “Problems of Projection” (POP). Each theoretical innovation is examined from the perspective of Chomsky’s main goal of explanation via simplification, while remaining and newly generated questions are discussed. Specifically, in each developmental stage of the theory, EKS focuses on labeling, projection, and the evolution of Simplest Merge, leading to a significant reduction of Universal Grammar (UG). Simplest Merge in POP, combined with the increased role of 3rd factor, is argued to yield greater explanatory depth, thereby reducing UG and the number of currently unanswerable scientific questions regarding its evolution.