Metadiscourse is a term that is used in philosophy to denote a discussion about a discussion (and so on), as opposed to a simple discussion about a given topic. The term metadiscourse is also used in writing to describe a word or phrase that comments on what is in the sentence, usually as an introductory adverbial clause. It is any phrase that is included within a clause or sentence that goes beyond the subject itself, often to examine the purpose of the sentence or a response from the author. Metadiscourse includes phrases such as "frankly," "after all," "on the other hand," "to our surprise," and so on.