As my military history course begins next week, I’m reminded of this quotation that’s on my syllabus in the face of people who, for whatever reason, oppose it being taught.

Anyone who clings to the historically untrue—and thoroughly immoral—doctrine that violence never settles anything I would advise to conjure up the ghosts of Napoleon Bonaparte and the Duke of Wellington and let them debate it. The ghost of Hitler would referee. Violence, naked force, has settled more issues in history than has any other factor, and the contrary opinion is wishful thinking at its worst. Breeds that forgot this basic truth have always paid for it with their lives and their freedoms.

–Robert Heinlein