 If Leonard Bloomfield is the intellectual ancestor of Externalism, and Sapir the father of Emergentism, then Noam Chomsky is the intellectual ancestor of Essentialism. The researcher with predominantly Essentialist inclinations aims to identify the intrinsic properties of language that make it what it is. For a huge majority of practitioners of this approach—researchers in the tradition of generative grammar associated with Chomsky—this means postulating universals of human linguistic structure, unlearned but tacitly known, that permit and assist children to acquire human languages. This generative Essentialism has a preference for finding surprising characteristics of languages that cannot be inferred from the data of usage, and are not predictable from human cognition or the requirements of communication.