The main thesis of this dissertation is that morphological case is a purely morphological phenomenon, determined exclusively within the post-Spell-out portion of the derivation on the branch leading to PF. As such, case will depend in large part on the output of the pre-Spell-out narrow syntax, but the narrow syntax will not be able to make reference to or depend in any way on morphological case. I motivate this thesis by presenting extensive evidence that, contrary to what has been assumed since the late 1970s, morphological case is completely independent of the principles of positional DP-licensing that have been called syntactic or abstract Case. I then examine a series of syntactic phenomena which have been argued to depend crucially on...