To an outsider looking at linguistic theory, the problem of internal vs. external evidence seems to arise out of a conflation of two relatively distinct enterprises. The first of these tries to establish a claim that there is a distinct, organic, language faculty (a language organ), that is, a species-specific characteristic common to all humans. The second is an attempt to abstract from the facts of diversity a structure that has equivalent universal characteristics and thus can be seen as an ideal type or as an ideal initial state condition (of a pure and uniform experience) under which a language is acquired by a native speaker. As I understand it, the relationship between these two enterprises is yet to be fully determined given the fact that the physical mechanism that has been deduced to correspond to a property of mind is as of now largely unknown.