Through his work Leonard Bloomfield brought much order into the field of linguistics, pointing out important rules that lead the development of every language. He saw order and principles at work where others saw random, meaningless processes affecting changes in languages. Through his efforts he made linguistics more exact, bringing it into acceptance as a scientific discipline.
However, on the other hand, Bloomfield overemphasized the mechanical aspects in language, reducing human speech to the level of mere stimulus-response processes. He deliberately ignored "mentalism" and cognitive processes, focusing on the external form, the sounds of language, rather than "the meaning" of language in its social context. Thus, he studied the physical structure of language only, disregarding the internal, mental side of language, that which makes it essentially human.