What are the similarities and differences in the development of Themes?

The difference and similarities is based around the relative nature of the themes.

Explanation:

Themes in an artwork are like mind maps.

They exist in many places in the work and throughout it they are adding more facets to the general themes.

These themes also exist prior to the work and the work is also adding on to the treatment of the themes too.

Some themes are more common and rather to use the word, universal. They concern more people and have been thought about often. These are the similar themes.

Some themes are remarkably new or that come out of the creativity of the author. Often they can be turned in with the universal themes too however.