In the chapter some preliminary methodological issues are discussed, including the demarcation between logic and linguistics and the shortcomings of empirical base of the theory of syntax. An epistemological approach to language is sketched out and a need for the proper balance between logical aspects of natural language and vernacular usage is claimed crucial for any reliable theory of syntax and semantics. Learnability and efficiency are presented as the most important constraints to be imposed upon a logical analysis of language.