This quote suggests that a well-balanced society is one where differing interests coexist and interact in harmony, much like the different elements in a piece of music. Each interest, like each note or instrument in a song, has its own unique character and purpose. When these interests are allowed to express themselves fully and interact with each other in a balanced and respectful manner, they can create a beautiful, dynamic society, just as different musical elements can create a beautiful, dynamic song.

The term "jarring interests" implies that these interests may initially seem to conflict with each other, or ‘jar.’ However, Pope suggests that it is not only possible, but also beneficial, for these conflicting interests to coexist and interact harmoniously. This is because the tension between different interests can stimulate dialogue, innovation, and progress, much like the tension between different musical elements can stimulate beautiful, moving music.

In today’s world, this quote can be applied to various areas, from politics and social issues to personal development. In politics, for example, a well-mixed state could be one where different political parties or factions coexist and interact in a balanced and respectful manner, rather than trying to suppress or eliminate each other. This can lead to a more dynamic, innovative, and resilient political system.

In terms of personal development, this quote can be seen as an encouragement to embrace and integrate our different interests, passions, and aspects of our personality, even if they seem to conflict with each other. For example, one might have an interest in both arts and sciences, or be both introverted and extraverted. Instead of seeing these as contradictory and trying to suppress one or the other, one can try to express and balance these different interests or aspects, and thereby create a richer, more dynamic personality.