In Donald Kagan's analysis of Thuycidides history if the Peloponnesian War Kagan makes this exact claim about Thuycidides historical writing. That Thuycidides wrote his history as a document which would serve as a tool for all time so that people in the future could look back on the past and understand. He further claims the Thuycidides strategically adds and omits certain details which Kagan speculates serves to further refine Thuycidides chosen narrative about his time and his role in the events.