Prescriptivism and Descriptivism: 

Prescriptivism – The attitude or belief that one variety of a language is superior to others and should be promoted as such. A key aspect of traditional grammar, prescriptivism is characterized by a concern for "good," "proper," or "correct" usage. It contrasts with descriptivism.

Descriptivism – A non-judgemental approach to language that focuses on how it is actually spoken and written. Contrast with prescriptivism.

Well known prescriptivists include:

Skinner

Pullum

Dryden

Bernstein

Crystal

Well known descriptivists include:

Chomsky 

Wrenn

Williams

Webster

Noam Chomsky, a famous linguist, has a descriptivist point of view. He believes that language is innate which fits in to the view that prescriptivism in language is artificial language and descriptivism is natural. However he also sees the other side to the argument that the specifics of standard grammar in Standard English should be learnt as part of an education – “I think sensible prescriptivism ought to be part of an education”. – Noam Chomsky 1991. This view shows a non negative attitude to variations in accent in dialect unlike prescriptivism which is arguably the source of negative attitudes towards accents like that of the ‘stealing’ Scouse or the ‘unintelligible’ Brummy.