What is the fine-grained topic of the following text: Furthermore, he contends, while political fights are healthy and often productive, at some point, society seems to have slipped into “unhealthy” territory, where people have become too divided upon party lines, too divided in terms of where they live and too unwilling to stay humble and open when it comes to admitting what they might be wrong about. Only return the topic.
Political division and lack of humility in admitting mistakes