For some time now, generative grammarians have been committed to reducing the role of the phrase structure rules in the grammar in favor of general principles. It has been observed that there is considerable redundancy in a grammar containing both phrase structure rules and subcategorization frames for lexical items or classes of lexical items. An attractive solution is to abandon the former in favor of the latter, together with a Projection Principle according to which the argument structure of lexical items is projected into the syntax. The single most serious problem with this approach is the apparent necessity for clauses, at least in English and many other languages, to have subjects - a requirement that is independent of the argument structure of the lexical items in the clause. The Extended Projection Principle reflects this problem very directly: although Chomsky claims that [the] Projection Principle and the requirement that clauses have subjects are conceptually quite closely related [Chomsky 82, p.10], it is not at all clear what the nature of the conceptual relation is
