Horror is a genre of speculative fiction which is intended to frighten, scare, disgust, or startle its readers by inducing feelings of horror and terror. Literary historian J. A. Cuddon defined the horror story as "a piece of fiction in prose of variable length... which shocks, or even frightens the reader, or perhaps induces a feeling of repulsion or loathing". It creates an eerie and frightening atmosphere. Horror is frequently supernatural, though it might be also non-supernatural. Often the central menace of a work of horror fiction can be interpreted as a metaphor for the larger fears of a society.