Halliday & Matthiessen (1999: 445):
After characterising the position of 'natural logic' in this way, Whorf (op cit.: 211) goes on to identify two problems with it:Natural logic contains two fallacies: First, it does not see that the phenomena of a language are to its own speakers largely of a background character and so are outside the critical consciousness and control of the speaker who is expounding natural logic. Hence, when anyone, as a natural logician, is talking about reason, logic, and the laws of correct thinking, he is apt to be simply marching in step with purely grammatical facts that have somewhat of a background character in his own language or family of languages but are by no means universal in all languages and in no sense a common substratum of reason.Second, natural logic confuses agreement about subject matter, attained through use of language, with knowledge of the linguistic processes by which agreement is attained: i.e., with the province of the despised (and to its notion superfluous) grammarian.