Contextual linguistics
Contextual linguistics is that realm where linguistics interacts with other academic disciplines. Whereas core theoretical linguistics studies languages for their own sake, the inder-disciplinary areas of linguistic consider how language interacts with the rest of the world. But that rather depends upon their world-view.
Sociolinguistics, anthropological linguistics, and linguistic anthropology are where the social sciences that consider societies as whole and linguistics interact.
Critical discourse analysis is where rhetoric and philosophy interact with linguistics.
Psycholinguistics and neurolinguistics is the where the medical sciences meets linguistics.
Other cross-disciplinary areas of linguistics include language acquisition, evolutionary linguistics, stratificational linguistics, and cognitive science.
Individual speakers, language communities, and linguistic universals
Linguists also differ in how broad a group of language users they study. Some analyze a given speaker's language or language development in great detail. Some study language pertaining to a whole speech community, such as the language of all those who speak Black English Vernacular. Others try to find linguistic universals that apply, at some abstract level, to all users of human language everywhere. This latter project has been most famously advocated by Noam Chomsky, and it interests many people in psycholinguistics and cognitive science. It is thought that universals in human language may reveal important insight into universals about the human mind.
Description and prescription
Most work currently done under the name "linguistics" is purely descriptive; the linguists seek to clarify the nature of language without passing value judgments or trying to chart future language directions. Nonetheless, there are many professionals and amateurs who also prescribe rules of language, holding a particular standard out for all to follow.
Whereas prescriptivists might want to stamp out what they perceive as "incorrect usage", descriptivists seek to find the root of such usage; they might describe it simply as "idiosyncratic", or they may discover a regularity that the prescriptivists don't like because it is perhaps too new or from a dialect they don't approve of.
Speech versus writing
Most contemporary linguists work under the assumption that spoken language is more fundamental, and thus more important to study, than writing. Reasons for this standpoint include:
- Speech appears to be a human universal, whereas there are and have been many cultures that lack written communication;
- People learn to speak and process oral language easier and earlier than writing;
- A number of cognitive scientists argue that the brain has an innate "language module", knowledge of which is thought to come more from studying speech than writing.
Of course, linguists agree that that the study of written language can be worthwhile and valuable. For linguistic research that uses the methods of 
