The most common has been conquest by war . In time, though, this method fails, because the captives hate the captors. Eventually the captives rise up and attempt to drive out the captors. Much force is needed to maintain control, making it expensive for the conquerors. Such a captivity is vulnerable to philosophical exposure or by overthrow through armed force, since modern religion by its nature lacks military force to regain control once its captives become disillusioned.
Political ideology is the third method of conquest.
Compulsory state education is the foundation. Children are forced into schools where the moral and political values of the ruling class are subtly imparted. They are taught submission to authority. The law of the authority is absolute and must be obeyed. The discipline of the clock is stressed.