Indiana University-Purdue University Indianapolis (IUPUI) / This thesis applies the ontological turn to the war fiction of veteran authors, Kurt Vonnegut and Tim O’Brien. It argues that some veteran authors desire to communicate truth through fiction. Choosing to communicate truth through fiction hints at a new perspective on reality and existence that may not be readily accepted or understood by those who lack combat experience. The non-veteran understanding of war can be more informed by entertaining the idea that a multiplicity of realities exists. Affirming the combat veteran reality—the post-war ontology—and acknowledging the non-veteran reality—rooted in what I label “pre-war” or “civilian” ontology—helps enhance the reader’s understanding of what veteran authors attempt to communicate through fiction. This approach reframes the dialogic interaction between the reader and the perspectives presented in veteran author’s fiction through an emphasis on “radical alterity” to the point that telling and reading such stories represent distinct ontological journeys. Both Kurt Vonnegut and Tim O’Brien provide intriguing perspectives on reality through their fiction, particularly in the way their characters perceive and express morality, guilt, time, mortality, and even existence. Vonnegut and O’Brien’s war experiences inform these perspectives. This does not imply that the authors hold an identical perspective on the world or that combat experience yields an ontological understanding of the world common to every veteran. It simply asserts that applying the ontological turn to these writings, and the writings of other combat veterans, reveals that those who experience combat first-hand often walk away from those experiences with a changed ontological perspective.