I learned in a theory class last year that people have a tendency to think that the way things are are the way things have always been and always will be. Before the Enlightenment, people had a good reason to believe this. For centuries of feudalism everyone followed the feudal ideology living lives defined by birth, and going to war only when the royalty or pope needed them to for the purpose of the Crown or the Church.
Until the Scottish rebellion marked the beginning of a zeitgeist that would not really be sensed until the French Revolution. Once that happened, the Western world realized the world can be changed. The Way Things Have Always Been need not be! People have an ability to literally change ideology, alter classes, abolish rulership within a generation, that would have been considered literally impossible only decades earlier.