I Am Legend stands out in American literature because Richard Matheson manages to combine two previously separate genres in a unique and subversive style. He blends gothic horror (which was considered a dead genre at the time) and science fiction in order to comment on themes of societal change and evolution.

In developing this new “pulp” style, Matheson’s purpose seems to have many layers. On the surface, his purpose is to entertain his readers with engaging prose. Upon more careful examination, Matheson’s deeper purpose seems to be to tell a cautionary tale about what can happen when societies and individuals fail to adapt to changing times. This warning can be charted by following Matheson’s intent throughout the novel. Humanity caused the vampire mutation, resulting in a consumptive hive-mind that destroys the human race. Robert Neville fails in his efforts to restore the humanity of his vampire test subjects. When Ruth offers Neville a chance to be a part of a new society that manages its mutations with medication, Neville chooses death instead. It is implied that the new world order will be run by this “third” set of people evolved from humans and vampires.

On a meta-stylistic level, Matheson demonstrates that two separate genres can evolve into a successful “third” as well. He seems to ask his audience to embrace change and be willing to take risks in order to help literature and society evolve in a positive direction.