Suppose, for instance, that the speaker-hearer's linguistic intuition does not readily tolerate the traditional practice of grammarians. If the position of the trace in (99c) were only relatively inaccessible to movement, an important property of these three types of EC may remedy and, at the same time, eliminate the requirement that branching is not tolerated within the dominance scope of a complex symbol. A consequence of the approach just outlined is that most of the methodological work in modern linguistics suffices to account for a descriptive fact. However, this assumption is not correct, since any associated supporting element is not to be considered in determining an important distinction in language use. We have already seen that a subset of English sentences interesting on quite independent grounds is not subject to irrelevant intervening contexts in selectional rules.
see also: WikiPedia -- Chomskybot