Help me choose a question for my dissertation

So im gonna do my dissertation on the prophet by kahlil gibran.l at advanced higher english level.
But I don't really know what to write my dissertation about. What would be a good question to answer in my dissertation about this book?
So far I am thinking about this question: how existentialism is explored in the prophet via use of imagery.
But I don't know if that's good

(edited 3 months ago)