Linguistics is usually defined as‘the science of language’or‘the systematic study of language’.As a science，it cultivates a rational outlook upon language.The linguist takes an objective view of language and all linguistic phenomena.In that respect linguistics follows the tradition set by the study of‘comparative philology’in the nineteenth century.But it differs from the approach to language cultivated in schools.Educators frequently recognize the‘good’or‘bad’，the‘right’or‘wrong’in language and point out the‘value’of a creative approach to the use of language.They express respect for language in works of literature.They may also appreciate the therapeutic and releasing value of the use of language.Value judgments about languages are quite common：‘French is a beautiful language.’‘Language X sounds ugly.’An objective approach to language is often condemned.The study of grammar is frequently described as‘dull’or‘arid’.Linguists do not deny that language use has a strongly emotional component and that language can be valued aesthetically.But as linguists，they study language and reflect on it in a detached and dispassionate way：‘This is the way Lx functions.’‘This is the way Ly is.’‘This is a characteristic of all languages’.‘It is a language universal’and so on.

Linguistics is a theoretical science.It is also empirical science which makes detailed observations on particular languages to confirm or refute generations.It formulates explanations that are designed to account for the‘phenomena of language’.For many linguistic scholars，the central purpose of linguistics is the development of theories on aspects of language and a general theory of language.The nineteenth century linguistics，too，had been interested in making general statements about language，but these tended to be laws accounting for phenomena in particular languages or groups of languages rather than about the nature of language in general.

Here is an obvious difference between a language teacher and a linguist.The language educator is concerned with the teaching of a particular language，for example，Chinese，French，English，or some aspect of the language，for example，reading in‘English’.His main concern‘usually’is not language in general，although teaching a particular language offers good opportunities for making observation on the nature of language.It has in fact been said that one of the best ways of understanding the nature of language is to try to teach（or learn）a language！

These two characteristics are in no way antithetical；on the contrary，they support each other.But the emphasis on theory or description has varied among the scholars.Some regard the descriptive tasks as the object of linguistics.Linguistics is for them a largely‘taxonomic’science like botany，concerned with the identification and ordering of many observations of plants in botany or language data in linguistics.Others regard the theoretical statements about language，the discovery of language‘universals’，and，thus，the creation of an understanding of the essential nature of language as the most important preoccupation of linguists.