[Here is a somewhat more expanded version of [34795].]

Chomsky (1965: 4) remarks that "linguistic theory is mentalistic, since it is concerned with discovering a mental reality underlying behavior" and in note 1 (p. 193) appended there states that "[m]entalistic linguistics is simply theoretical linguistics that uses performance as data (along with other data, for example, the data provided by introspection) for determination of competence, the latter being taken as the primary object of its investigation." The research reported in this book is mentalistic linguistics in the above sense, and the book's aim is to put forth and defend a means to determine, with some confidence, when to take a certain set of informant judgments as a reflection of properties of the Computational System, hypothesized to be at the center of the language faculty. The book addresses how we can approach, and formulate our hypotheses, about the Computational System in a way empirically testable, presents a conceptual basis for its proposal and provides empirical illustration of the methodological proposals.
Among the general theses put forth and defended in this book are:

--The empirical justification for our hypotheses about the Computational System as to whether and in what way they are linked to native speakers' linguistic intuitions.^{Note 1}
--It is not a priori clear what linguistic intuitions are likely to be a reflection of, and hence revealing about, properties of the Computational System; given our goal, identifying such linguistic intuitions is in fact part of the task of the researcher.
--There is a way to identify such linguistic intuitions.
--Once we adopt a means to identify such linguistic intuitions, we can capitalize on it in evaluating the empirical consequences of our hypotheses about the Computational System.

One of the main methodological points of the book is its claim that it is possible to, and we in fact should proceed so as to be able to, learn something about the Computational System from the disconfirmation of a certain type of predictions.

Note 1: Cf. Einstein and Infeld's (1938: 294) "Science is not just a collection of laws, a catalogue of unrelated facts. It is a creation of the human mind, with its freely invented ideas and concepts. Physical theories try to form a picture of reality and to establish its connection with the wide world of sense impressions. Thus the only justification for our mental structures is whether and in what way our theories form such a link." (in 'Physics and Reality', the last section of The Evolution of Physics by Einstein and Infeld, originally published in 1938. The page reference is to the 2007 edition, Simon & Schuster, New York.) See also "Summary" of "Physics and Reality" in Einstein 1936/1954, p. 322. Bridging statements, to be introduced in chapter 3, are none other than an attempt to link our hypotheses about the properties of the Computational System (CS) with the 'sense impressions' as hypothesized to arise from the postulated properties of the CS.