The dissertation seeks to pursue the essential properties of literature, i.e. literariness. Foregrounding is widely considered by stylisticians to account for literariness. However, foregrounding theory mainly focuses on linguistic level to define ’literariness’. The problem is linguistic patterning and deviation are also commonly seen in works outside the literary canon, such as advertisements, news articles etc. There exists another problem: Upon reading a certain text, different people will render different understandings, and will have disagreements about whether the text is literary or not. The dissertation attempts to find an explanation for this phenomenon by incorporating readers’ role in the literary experience. The argument is that most of the literary discourse has the ability to effect changes in readers’ mind, that’s where ’literariness’ lie in. In the beginning, some differing views upon the definition of ’literariness’ by different scholars are offered. The perspectives range from traditional stylistics to modern cognitive psychology. In the following section a development of schema theory will be described to further explore reader’s psychology in the literary experience. I then go on to analyse schema theory’s important contributions to literature processing and also its inability to characterize ’literariness’. That’s when Guy Cook’s theory of discourse deviation comes in. Guy Cook’s theory will be dealt with at great length in the 3rd chapter. In the 4th chapter, several examples of discourse deviation are analyzed to further support Cook’s theory. A conclusion is drawn in the last chapter.