Critics refer often to literary movements, citing different movements that have developed in literature and then been replaced by some other movement. Generally, the term is not defined, and instead it is simply assumed that everyone is talking about the same thing when the term is used. J.A. Cuddon offers a definition that is too simple to be more than a beginning: "A term commonly applied to a trend or development in literature" (Cuddon 558). Cuddon's definition contains the necessary elements, but they are not fully explained. The important word in his definition is "trend" rather than "development," for the latter is too unspecific and could refer to a literary device or idea used by one writer. A literary movement must be a trend, meaning that it is subscribed to by a number of writers who make use of the ideas and techniques that define a given movement. To be a movement, it must also be differentiated from other movements and not be merely a variation on an existing theme or a core group following an old trend. A literary movement has to be identified, meaning someone has to notice that there is a trend and that there is a group of writers who are making use of it in their work. A movement may declare itself--some movements have been created and expressed through manifestoes and overt statements of principle. Other movements may come about because there is something "in the air," as it were, so that a number of writers begin making use of a given technique, style, or idea. This becomes a movement when it is identified as such, though in effect it begins without such identification.
Consider some of the literary movements that have been identified and described by writers and critics. The Dada movement was created in Zurich in 1916 with the poetry of Hans Arp, published in a pacifist newspaper:
For Arp poetry was a necessary means of expressing his essentially surrealistic response to existence: childlike, ...