Although Clausewitz used the theory of war as a model to explain "what had happened" in the history of war, Delbruck considered this theory as a "corrective to what that the sources told us.”1 Claueseiwitz advocated the use of “historical example” to determine the nature of war. He emphasized the four uses that history has to offer: “an explanation, a demonstration of the application of an idea, as support for a statement and as a detailed presentation from which a doctrine might be deduced.” It also establishes varying degrees of rigor: The first and simplest requirement is accuracy ability to discern and a basis for comparison that will develop a sense of accuracy. The second and by far greater need is to project ourselves into the moment under consideration, not to force it into our conquered world. Only by understanding the conditions of the time and the perspectives of the people studied can we understand the logic of their decisions and make judgments for our time. The third and fourth are questions of logic and discipline. Delbruck saw this as both a good and bad thing for the history of war and warfare. This allowed for the creation of a “synergistic relationship between theory and empirical research long before this became the case in most other branches of historical writing.” He, however, argued that this allowed historians of war and warfare to be selective with their sources and reject them if they did not support or “exemplify some dogma or theory.” This was amplified by the fact that many military/war historians had “professional-level teaching functions,” teachers in military institutions focused on “proposing the principles of war” and ignored “the uncertainties and elusiveness of past reality… in the middle of the sheet. .....aphy. More importantly, it will show students how Dulbrek improved military history not only by focusing on technical details but also by taking into account contextual, social, and economic aspects. He was also an advocate of history with pragmatic applications and was able, to some extent, to bring it into academia despite initial firm rejection by the academic community; however, as this article has previously examined, pragmatic applications of history conflict with histiography and the issue remains unresolved. Another reading I was seriously considering was On War by Carl von Clausewitz, the first military historian who used the "theory of war" and instigated the first historical change in military historiography, but I chose Dulbrek's because his influence on the changes in military historiography were the most important examined by this article.