The theories and writings of Clausewitz (the entire oeuvre) so clearly stand in contrast to any military writing that came before him that it is hard to not say he must have also been doing something entirely new. There are great works before On War, but they tend to be the interesting but still un-insightful recollections of a great leader, succinct manuals or guides, or, like de Saxe's Reveries on the Art of War, they tend to be snap shots of some of war's perceived qualities only. Clausewitz was unique. He was building theories that interrelated and formed larger theories, his thought evolved (like Kant or any accomplished philosopher), and he was attempting to do more than just record for posterity or personal vanity. He was also conscious of the revolutionary basis of his work.
It helped that Clausewitz was intellectually speaking a "reformer" (though, also, not too much should be made of this because considering the times, he can also be seen as traditional, if not reactionary). His reformist mind made him comfortable with the idea that war had no set of immutable rules of conduct that could ensure success. Clausewitz studied closely the leading military thinkers who were his peers, and those of the eighteenth century, but also strongly felt that they were, so to speak, "missing the point." What set Clausewitz apart was that he was searching for an enduring theory of war that "could not be wrapped in a strict formulaic model."
Yes, Clausewitz does qualify as searching for the truth about war. One of the first things he discovered is that there is not one truth about war but many. He explored a "rational" (and also measurable) view of war then determined that such a view was only an ideal. Although this ideal form could help us to understand war it would also never be experienced in the real world. Then, considering the trinity, relationship between politics and warfare, and the decisive roles of chance and genius, we are left with many different truths. Some of these truths are based on a kind of war (limited, for example) or a particular historical period (the ancien regime, for example). Because of his philosophical background, I do conclude that he was looking for a fundamental reality of war, using a phenomenological approach. But his work was unfinished, and since I agree with Christopher Bassford's characterization of Clausewitz as intellectually honest and rigorously analytical, it is hard for me to say where his revisions would have taken him--ultimately.
There is nothing inherently materialistic in the search for war's true nature; war does not reduce to mathematical models despite the impression given by Lancaster equations. Advances in science and especially experimental methods, industrialization, mass production and mass armies, gave the art of war throughout the modern period a strong mathematical quality. I still believe this is a reflection of the social fabric rather than the nature of war itself. Part of what makes me think this is more than three thousand years of record Chinese history (but only up to the end of the Qing) and I have yet to find any comparable period where quantification dominates like it does in military affairs today.
1. See David MacIsaac, "Master at Arms: Clausewitz in Full View," Air University Review, January-February 1979: 83-93.
2. Belinda Heerwagen, Carl von Clausewitz and His Relevance as a Contemporary Theorist (Carlise, PA: U.S. Army War College, Strategy Research Project, 2007), 2. The supreme irony is that generations of military professionals have done exactly that, reduced him to three or four pat formulas.
3. Christopher Bassford, "Jomini and Clausewitz: Their Interaction," The Clausewitz Homepage, website, http://www.clausewitz.com/CWZHOME/Jomini/JOMINIX.htm, accessed 6 August 2008.