After more books on the subject, six novels, and numerous classes, I finally understood. According to Rust Hills, theme is the book’s value or meaning or what it has to say. Another way to phrase this might be the story’s underlying message.
Aside from the plot and character development, what are you trying to convey to the reader? If you write love stories, what are you saying about love? Does it always work out? Or does life get in the way? If you write action stories, does good triumph over evil? Do you have a political or social message you want to share with your audience?
Theme develops and grows with the characters and their situations. The hero may not know his intended direction at the beginning of the book, but shortly afterward he must acknowledge it and either embrace it or reject it. A complicated and emotional drama may have the hero vacillate between duty and passion, never sure which he will choose until he faces that moment of decision.
Some well-known themes and their associated works are listed below:
Good vs. Evil
Here the good guy battles aliens, crooks, super robots, vampires, magicians, etc. Two famous books in this category are The Lord of the Rings and Harry Potter.
What would the world do without romance? Jane Austen captures the agonies of love beautifully in Pride and Prejudice. Shakespeare shows that love sometimes cannot conquer the odds in Romeo and Juliet.
Man vs. Nature
Man is superior in all things, right? Maybe, maybe not. In Swiss Family Robinson humans triumph over nature. Jurassic Park shows the reverse with nature run amok. Science fiction often shows the delicate balance that must exist between man and technology.
Fate vs. Free Will
Is someone else controlling your life? Ancient cultures believed that the gods and goddesses ruled the lives of humans. Many cultures today believe that a higher power watches over them and helps direct the course of their lives. Oedipus Rex ends with an unhappy ending to this dilemma. Cinderella demonstrates the happily-ever-after outcome.
Triumph over Adversity
Can you make lemonade from those lemons? Scarlett O’Hara did in Gone with the Wind. So did Oliver Twist. Not so fortunate was the fisherman in Old Man and the Sea.
Before you write your next book or short story, think about your theme. What idea do you want to illustrate? Is it that love conquers all? Man and nature need to exist in harmony? Life is predestined? Whatever the idea, explore it before you write, then carry that theme throughout your writing.