Essays / Essay topic sentences (using 4 books that we studied in my english class) [4]

Hi guys,

I have to write an essay that requires me to use 4 books that we studied in my english class. If I want to split my body paragraphs so that each one is for one book, how would I go about doing that? Lets say my thesis is "The characters in the studied works become better people after smoking."

Would my topic sentences have to explain WHY the characters became better people after smoking? Or can I just use "John from The House by ...becomes a better person after smoking." without stating why he became a better person?

Please help! I'm confused!