Irrealism is a term that has been used by various writers in the fields of philosophy, literature, and art to denote specific modes of unreality and/or the problems in concretely defining reality. While in philosophy the term specifically refers to a position put forward by the American philosopher Nelson Goodman, in literature and art it refers to a variety of writers and movements. If the term has nonetheless retained a certain consistency in its use across these fields and would-be movements, it perhaps reflects the word's position in general English usage: though the standard dictionary definition of irreal gives it the same meaning as unreal, irreal is very rarely used in comparison with unreal. Thus, it has generally been used to describe something which, while unreal, is so in a very specific or unusual fashion, usually one emphasizing not just the "not real," but some form of estrangement from our generally accepted sense of reality.