The focus of this work, supposedly written by Longinus, although the majority of critics believe that it would have been another author who penned this work of early criticism, is the characteristics of sublime literature. These, the author lists and explores in turn. This text begins with a discussion about the relationship between "nature" and "art," or natural genius and learnt skills and talents. Having stated that natural genius is essential for sublime literature to be produced, but that this must also be coupled with "art" in the form of learnt skill, Longinus goes on to state the requisites of sublime literature, which can be identified in the impact such work has on the reader:
For, as if instinctively, our soul is uplifted by the true sublime; it takes a proud flight, and is filled with joy and vaunting, as though it had itself produced what it has heard.
Sublime literature, therefore, which is the focus of this early piece of literary criticism, is above all recognised by the emotional impact that it has on the audience. Longinus then states that there are five sources of "elevated language": creativity, passion, the use of figures of expression, noble diction and finally dignified composition. He then explores each in turn and looks at examples of what constitutes "sublime" literature and what does not.