Horror is perhaps the most unfairly maligned of genres, probably because, like pornography (with which it has often been associated by the arbiters of public taste) it explicitly seeks to provoke a specific emotional response. The genre has rarely been satisfactorily defined. This is partially because “unlike fantasy, Supernatural Fiction and Science Fiction – terms which describe generic structures – Horror is a term which describes an affect. A Horror story must make its readers feel horror” (The Encyclopedia of Fantasy, 478).
In his essay “Horror Fiction: In Search of a Definition”(2000), Clive Bloom provides some idea of the complexity of the issue when he notes that there exists “a …
Murphy, Bernice. "Horror". The Literary Encyclopedia. First published 17 September 2004
[http://www.litencyc.com/php/stopics.php?rec=true&UID=518, accessed 25 March 2017.]