Carl von Clausewitz

Carl Philipp Gottfried (or Gottlieb) von Clausewitz (1 July 1780 – 16 November 1831) was a Prussian general and military theorist who stressed the "moral" (in modern terms meaning psychological) and political aspects of waging war. His most notable work, Vom Kriege ("On War"), though unfinished at his death, is considered a seminal treatise on military strategy and science.