"This research survey combines an introduction to Phase Theory with an assessment of the state of the art in Phase Theory. The term Phase Theory refers to a set of theoretical innovations in post-2000 minimalism (Chomsky 2000RFA-087, 2001RFA-088, 2004RFA-089, 2005RFA-090, 2008RFA-092). One of the core ideas in minimalism is the idea that the language faculty is an optimal solution to the constraints imposed on it by the two cognitive systems with which it interacts:"-- Provided by publisher.