[…] linguists, in their efforts to understand how language changes, should undoubtedly take advantage of information theory, but that they should thereby keep in mind that, in any speculation involving cost, i.e. in our case, energy spent toward storage and production, or if we prefer, memorization and actual use in speech, they will have to avoid attempts at mathematica formulation.
- Martinet (1962), a pag.141

Linguists, once they have ascertained the decisive influence exerted by social factors on linguistic structure, should not try to do what they are trained to do and what might lead them into realm of unverifiable hypotheses, namely to examine the details of that influence and venture into field of cultural history. The real task is to observe and describe, within a given language and through a limited period, the various conflicts and trends in the frame of the permanent needs of human communication. In order to understand how and why a language changes, the linguist has to keep in mind two ever-present and antinomic factors: first the requirements of communication, the need for the speaker to convey his message, and, second, the principle of least effort, which makes him restrict his output of energy, both mental and physical, to the minimum compatible with achieving his ends.
- Martinet (1962), a pag.138-139