Summary
This quote suggests that when a country isolates itself from the rest of the world and focuses solely on its own interests, it can lead to collective psychological disturbance or mental illness. By shutting oneself off from the global community, lacking diversity and exposure to different ideas, cultures, and perspectives, a nation can become overly introspective and develop an exaggerated and unhealthy sense of superiority or inferiority. Therefore, the quote highlights the importance of international engagement and open-mindedness to foster a more well-rounded and mentally healthy society.