Since our sense experiences, such as introspective judgments about a given sentence in a given language, most likely reflect more than the language faculty proper (such as the 'pragmatic' knowledge about the usefulness of the given utterance, the knowledge about the real world, etc. --added here, HH), such a task necessarily involves hypotheses about the nature of the relevant sense experiences, in particular, hypotheses as to which aspects of our sense experiences under discussion are reflections of our grammar (proper --added here, HH), and in what theoretical terms they are to be expressed. At a particular stage of theory construction, a given factor can be reasonably considered grammatical in nature only if it can be expressed in terms of concepts postulated within the grammatical theory being developed.² Every concept and relation postulated in the theory, in turn, must be tightly related to the native speaker's linguistic intuitions---often quite indirectly---as reflections of his/her grammar. It is in fact the tight connection between (i) theoretical concepts and relations on the one hand and (ii) the speaker's linguistic intuitions on the other that makes it possible to put forth definite predictions about the latter that are formulated in terms of the former, thereby making the proposed theory/hypothesis falsifiable."

²  Chomsky (1955/1975: 61) thus states that "a field of investigation cannot be clearly delimited in advance of the theory dealing with the subject matter; in fact, it is one of the functions of a theory to give such a precise delimitation.

What I meant to say, but did not say, was that such tight connection is conspicuously missing in much of the works in the literature, making it difficult to argue, on the basis of the general practice in the field, that generative grammar is being practiced as an empirical science.