Had to do a quick search for this one, I had never come across the word before!

Leitmotif

noun

a recurrent theme throughout a musical or literary composition, associated with a particular person, idea, or situation.

• Wikipedia

Ooooh, now this is a good question!

I would say a recurring theme or element is the idea of individuality versus collectivism, and the relationship between them. Rather than just declaring one good / one bad, looking at how different cultures explore and implement them.