August Otto Rühle von Lilienstern, born 1780, died 1847. Prussian officer, joined Scharnhorst's Academy for Officers in the same promotion as Carl von Clausewitz. Later, they both taught at the Prussian General War School, which would become the War Academy, and Rühle would be Clausewitz' second successor as its director. Rühle published many articles, kept official war diaries, and wrote a two-volume Manual for the Officer for Education in Peace and for Use in Action (Handbuch für den Offizier zur Belehrung im Frieden und zum Gebrauch im Felde), published in Berlin in 1817 and 1818. From this Clausewitz, teaching at the same school at the time of publication of this manual, took, without acknowledgment, several ideas, including that about war as pursuing political aims, and war being a duel, which Clausewitz made famous in his book On War.