an Intellectual

"An intellectual is a person knowledgeable in one field who speaks out only in others."

One example is Noam Chomsky, a brilliant linguist who on his own figured out that language is a structure built into the very central nervous system of Homo sapiens, a theory that neuroscientists, lacking the instruments to do so heretofore, have only recently begun to verify. But Chomsky was not known as an intellectual until he denounced the war in Vietnam, something he knew absolutely nothing about—thereby qualifying for his new eminence.

- Tom Wolfe