The lack of proprieties would make the most intimate friends turn to be the most decided enemies and the friendly or allied countries declare war against each other.

• 这是一段类似比喻的类比，作者把社会比为火车和马车，把礼节类比为轨道、车轮和轴，火车只能沿着铁轨前行，马车只有靠车轮和轴才能前进。通过类比，作者得出结论：